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 #22847

This PR:

* introduce Gitea's own `showElem` and related functions
* remove jQuery show/hide
* remove .hide class
* remove inline style=display:none 

From now on:

do not use:
* "[hidden]" attribute: it's too weak, can not be applied to an element
with "display: flex"
* ".hidden" class: it has been polluted by Fomantic UI in many cases
* inline style="display: none": it's difficult to tweak
* jQuery's show/hide/toggle: it can not show/hide elements with
"display: xxx !important"

only use:
* this ".gt-hidden" class
* showElem/hideElem/toggleElem functions in "utils/dom.js"

cc: @silverwind , this is the all-in-one PR

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>

* Add main aria landmark to templates
 * Adjust some titles to improve understanding of location in navigation

Contributed by @Forgejo

* Refactor `i18n` to `locale`

- Currently we're using the `i18n` variable naming for the `locale`
struct. This contains locale's specific information and cannot be used
for general i18n purpose, therefore refactoring it to `locale` makes
more sense.
- Ref: https://github.com/go-gitea/gitea/pull/20096#discussion_r906699200

* Update routers/install/install.go

* Create finding files page ui in repo page

* Get tree entries for find repo files.

* Move find files JS to individual file.

* gen swagger.

* Add enry.IsVendor to exclude entries

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>