Enable us to use tailwind's
[`font-family`](https://tailwindcss.com/docs/font-family) classes as
well as remove `gt-mono` in favor of `tw-font-mono`. I also merged the
"compensation" to one selector, previously this was two different values
0.9em and 0.95em. I did not declare a `serif` font because I don't think
there will ever be a use case for those. Command ran:

```sh
perl -p -i -e 's#gt-mono#tw-font-mono#g' web_src/js/**/* templates/**/*

This will conclude the refactor of 1:1 class replacements to tailwind,
except `gt-hidden`. Commands ran:

```bash
perl -p -i -e 's#gt-(p|m)([lrtbxy])?-0#tw-$1$2-0#g'   {web_src/js,templates,routers,services}/**/*
perl -p -i -e 's#gt-(p|m)([lrtbxy])?-1#tw-$1$2-0.5#g' {web_src/js,templates,routers,services}/**/*
perl -p -i -e 's#gt-(p|m)([lrtbxy])?-2#tw-$1$2-1#g'   {web_src/js,templates,routers,services}/**/*
perl -p -i -e 's#gt-(p|m)([lrtbxy])?-3#tw-$1$2-2#g'   {web_src/js,templates,routers,services}/**/*
perl -p -i -e 's#gt-(p|m)([lrtbxy])?-4#tw-$1$2-4#g'   {web_src/js,templates,routers,services}/**/*
perl -p -i -e 's#gt-(p|m)([lrtbxy])?-5#tw-$1$2-8#g'   {web_src/js,templates,routers,services}/**/*
```

Commands ran:

```sh
perl -p -i -e 's#gt-font-light#tw-font-light#g' web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-font-normal#tw-font-normal#g' web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-font-medium#tw-font-medium#g' web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-font-semibold#tw-font-semibold#g' web_src/js/**/* templates/**/*
perl -p -i -e 's#gt-font-bold#tw-font-bold#g' web_src/js/**/* templates/**/*
```

Fixes https://github.com/go-gitea/gitea/issues/30005. Regression from
https://github.com/go-gitea/gitea/pull/29945.

There was only once instance of `tw-content-center` before that PR, so I
just ran below command and reverted that one instance.

```sh
perl -p -i -e 's#tw-content-center#tw-items-center#g' web_src/js/**/* templates/**/* models/**/* tests/**/*
```

To keep blame info accurate and to avoid [changes like
this](https://github.com/go-gitea/gitea/pull/29977/files#diff-c3422631a14edbe1e508c4b22f0c718db318be08a6e889427802f9b6165d88d6R359),
it's good to always have a trailing comma, so let's enforce it in JS.

This rule is completely automatically fixable with `make lint-js-fix`
and that's what I did here.

Likely the biggest change of the tailwind refactors. Only thing of note
is that `tw-flex-1` resolves to `flex: 1 1 0%` while our `gt-f1` was
`flex: 1 1 0`, I don't think it will make any difference. Commands I've
ran:

```sh
perl -p -i -e 's#gt-vm#tw-align-middle#g' web_src/js/**/* templates/**/* models/**/*
perl -p -i -e 's#gt-fw#tw-flex-wrap#g' web_src/js/**/* templates/**/* models/**/*
perl -p -i -e 's#gt-f1#tw-flex-1#g' web_src/js/**/* templates/**/* models/**/*
perl -p -i -e 's#gt-fc#tw-flex-col#g' web_src/js/**/* templates/**/* models/**/*
perl -p -i -e 's#gt-sb#tw-justify-between#g' web_src/js/**/* templates/**/* models/**/*
perl -p -i -e 's#gt-je#tw-justify-end#g' web_src/js/**/* templates/**/* models/**/*
perl -p -i -e 's#gt-jc#tw-justify-center#g' web_src/js/**/* templates/**/* models/**/*
perl -p -i -e 's#gt-ac#tw-content-center#g' web_src/js/**/* templates/**/* models/**/* tests/**/*
perl -p -i -e 's#gt-df#tw-flex#g' web_src/js/**/* templates/**/* models/**/* tests/**/*
perl -p -i -e 's#gt-dib#tw-inline-block#g' web_src/js/**/* templates/**/* models/**/* tests/**/*

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

Close #26730


1. The `diff-detail-box` was abused, it shouldn't be used for
"DiffFileList/DiffFileTree".
2. Fix the sticky position for various screens.



![image](https://github.com/go-gitea/gitea/assets/2114189/558a5c06-c94c-4e5c-8395-d38473dd21c2)


![image](https://github.com/go-gitea/gitea/assets/2114189/3390fb0e-7dc7-457f-bd0c-398fdb6d24c0)


![image](https://github.com/go-gitea/gitea/assets/2114189/d19dd350-aecf-4909-8ef9-73b09d94560e)

The [recommended order](https://vuejs.org/guide/scaling-up/sfc.html) for
SFC blocks is script -> template -> style, which we were violating
because template and script were swapped. I do find script first also
easier to read because the imports are on top, letting me immideatly see
a component's dependencies.

This is a pure cut-paste refactor with some removal of some empty lines.

---------

Co-authored-by: Lauris BH <lauris@nix.lv>

Follow  #21012, #22399

Replace #24983, fix #24938

Help #24956

Now, the `window.config.pageData.diffFileInfo` itself is a reactive
store, so it's quite easy to sync values/states by it, no need to do
"doLoadMoreFiles" or "callback".

Screenshot: these two buttons both work. After complete loading, the UI
is also right.

<details>


![image](https://github.com/go-gitea/gitea/assets/2114189/cc6310fd-7f27-45ea-ab4f-24952a87b421)


![image](https://github.com/go-gitea/gitea/assets/2114189/4c11dd67-ac03-4568-8541-91204d27a4e3)


![image](https://github.com/go-gitea/gitea/assets/2114189/38a22cec-41be-41e6-a209-f347b7a4c1de)

</details>

Enable
[`vue/html-closing-bracket-spacing`](https://eslint.vuejs.org/rules/html-closing-bracket-spacing.html)
and set it to never add any useless spaces inside tags. All issues were
fixed automatically with `make lint-js-fix`.

There was some recent discussion about this in Discord `ui-design`
channel and the conclusion was that
https://github.com/go-gitea/gitea/issues/24305 should have fixed their
OS font installation to have semibold weights.

I have now tested this 601 weight on a Windows 10 machine on Firefox
myself, and I immediately noticed that bold was excessivly bold and
rendering as 700 because browsers are biased towards bolder fonts. So
revert this back to the previous value.

Follow:
* #23574
* Remove all ".tooltip[data-content=...]"

Major changes:

* Remove "tooltip" class, use "[data-tooltip-content=...]" instead of
".tooltip[data-content=...]"
* Remove legacy `data-position`, it's dead code since last Fomantic
Tooltip -> Tippy Tooltip refactoring
* Rename reaction attribute from `data-content` to
`data-reaction-content`
* Add comments for some `data-content`: `{{/* used by the form */}}`
* Remove empty "ui" class
* Use "text color" for SVG icons (a few)

## TLDR

* Improve performance: lazy creating the tippy instances.
* Transparently support all "tooltip" elements, no need to call
`initTooltip` again and again.
* Fix a temporary tooltip re-entrance bug, which causes showing temp
content forever.
* Upgrade vue3-calendar-heatmap to 2.0.2 with lazy tippy init
(initHeatmap time decreases from 100ms to 50ms)

## Details

### The performance

Creating a lot of tippy tooltip instances is expensive. This PR doesn't
create all tippy tooltip instances, instead, it only adds "mouseover"
event listener to necessary elements, and then switches to the tippy
tooltip

### The general approach for all tooltips

Before, dynamically generated tooltips need to be called with
`initTooltip`.

After, use MutationObserver to:

* Attach the event listeners to newly created tooltip elements, work for
Vue (easier than before)
* Catch changed attributes and update the tooltip content (better than
before)

It does help a lot, eg:

1a4efa0ee9/web_src/js/components/PullRequestMergeForm.vue (L33-L36)

### Temporary tooltip re-entrance bug

To reproduce, on try.gitea.io, click the "copy clone url" quickly, then
the tooltip will be "Copied!" forever.

After this PR, with the help of `attachTippyTooltip`, the tooltip
content could be reset to the default correctly.

### Other changes

* `data-tooltip-content` is preferred from now on, the old
`data-content` may cause conflicts with other modules.
* `data-placement` was only used for tooltip, so it's renamed to
`data-tooltip-placement`, and removed from `createTippy`.

As discussed in #22847 the helpers in helpers.less need to have a
separate prefix as they are causing conflicts with fomantic styles

This will allow us to have the `.gt-hidden { display:none !important; }`
style that is needed to for the reverted PR.

Of note in doing this I have noticed that there was already a conflict
with at least one chroma style which this PR now avoids.

I've also added in the `gt-hidden` style that matches the tailwind one
and switched the code that needed it to use that.

Signed-off-by: Andrew Thornton <art27@cantab.net>

---------

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

- Replace all default exports with named exports, except for Vue SFCs
- Remove names from Vue SFCs, they are automatically inferred from the
filename
- Misc whitespace-related tweaks

Close #19902

This PR adds a filetree to the left side of the files/diff view.

Initially the filetree will not be shown and may be shown via a new
"Show file tree" button.

Showing and hiding is using the same icon as github. Folders are
collapsible. On small devices (max-width 991 PX) the file tree will be
hidden.

Close #18192

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>