"ogg" is just a "container" format for audio and video.

Golang's `DetectContentType` only reports "application/ogg" for
potential ogg files.

Actually it could do more "guess" to see whether it is a audio file or a
video file.

Close #17108

This PR uses a trick (removing the ID3 tag) to detect the content again
to to see whether the content is text type.

---------

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

Replace #23310, Close #19733

And fix various UI problems, including regressions from #22959 #22950
and more.

## SVG Detection

The old regexp may mismatch non-SVG files. This PR adds new tests for
those cases.

## UI Changes

### Before

![image](https://user-images.githubusercontent.com/2114189/222967716-f6ad8721-f46a-4a3f-9eb0-a89e488d3436.png)

![image](https://user-images.githubusercontent.com/2114189/222967780-8af8981a-e69d-4304-9dc4-0235582fa4f4.png)

### After

![image](https://user-images.githubusercontent.com/2114189/222967575-c21c23d4-0200-4e09-aac3-57895e853000.png)

![image](https://user-images.githubusercontent.com/2114189/222967585-8b8da262-bc96-441a-9851-8d3845f2659d.png)

![image](https://user-images.githubusercontent.com/2114189/222967595-58d9bea5-6df4-41fa-bf8a-86704117959d.png)

![image](https://user-images.githubusercontent.com/2114189/222967608-38757c1a-b8bd-4ebf-b7a8-3b30edb7f303.png)

![image](https://user-images.githubusercontent.com/2114189/222967623-9849a339-6fae-4484-8fa5-939e2fdacbf5.png)

![image](https://user-images.githubusercontent.com/2114189/222967633-4383d7dd-62ba-47a3-8c10-86f7ca7757ae.png)

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

- Always respect the user's configured mime type map
- Allow more types like image/pdf/video/audio to serve with correct content-type
- Shorten cache duration of raw files to 5 minutes, matching GitHub
- Don't set `content-disposition: attachment`, let the browser decide whether it wants to download or display a file directly
- Implement rfc5987 for filenames, remove previous hack. Confirmed it working in Safari.
- Make PDF attachment work in Safari by removing `sandbox` attribute.

This change will make a lot more file types open directly in browser now. Logic should generally be more readable than before with less `if` nesting and such.

Replaces: https://github.com/go-gitea/gitea/pull/20460
Replaces: https://github.com/go-gitea/gitea/pull/20455
Fixes: https://github.com/go-gitea/gitea/issues/20404

* gofumpt -w -l .

* gofumpt -w -l -extra .

* Add linter

* manual fix

* change make fmt

* Read expected buffer size.

* Changed name.

* Fix various doc, user-facing, and source comment typos

Found via `codespell -q 3 -S ./options/locale,./vendor -L ba,pullrequest,pullrequests,readby`

* Added type sniffer.

* Switched content detection from base to typesniffer.

* Added GuessContentType to Blob.

* Moved image info logic to client.
Added support for SVG images in diff.

* Restore old blocked svg behaviour.

* Added missing image formats.

* Execute image diff only when container is visible.

* add margin to spinner

* improve BIN tag on image diffs

* Default to render view.

* Show image diff on incomplete diff.

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Lauris BH <lauris@nix.lv>