fix(ui): unescape file names in commit hash links (#9182)

### What?
- `eeb243c339/path/to/file #.txt` instead of `eeb243c339/path/to/file%20%23.txt`, see [example on v13.next](https://v13.next.forgejo.org/mahlzahn/test/issues/3)

### Tests

- I added test coverage for Go changes...
  - [x] in their respective `*_test.go` for unit tests.
  - [ ] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- I added test coverage for JavaScript changes...
  - [ ] in `web_src/js/*.test.js` if it can be unit tested.
  - [ ] in `tests/e2e/*.test.e2e.js` if it requires interactions with a live Forgejo server (see also the [developer guide for JavaScript testing](https://codeberg.org/forgejo/forgejo/src/branch/forgejo/tests/e2e/README.md#end-to-end-tests)).

### Documentation

- [ ] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
- [x] I did not document these changes and I do not expect someone else to do it.

### Release notes

- [ ] I do not want this change to show in the release notes.
- [x] I want the title to show in the release notes with a link to this pull request.
- [ ] I want the content of the `release-notes/<pull request number>.md` to be be used for the release notes instead of the title.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/9182
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Reviewed-by: Lucas <sclu1034@noreply.codeberg.org>
Co-authored-by: Robert Wolff <mahlzahn@posteo.de>
Co-committed-by: Robert Wolff <mahlzahn@posteo.de>

modules/markup/html.go

@@ -557,9 +557,13 @@ func createCodeLink(href, content, class string) *html.Node {
 		a.Attr = append(a.Attr, html.Attribute{Key: "class", Val: class})
 	}
 
+	unescaped, err := url.QueryUnescape(content)
+	if err != nil {
+		unescaped = content
+	}
 	text := &html.Node{
 		Type: html.TextNode,
-		Data: content,
+		Data: unescaped,
 	}
 
 	code := &html.Node{

modules/markup/html_test.go

@@ -91,6 +91,9 @@ func TestRender_Commits(t *testing.T) {
 	test(sha[:14]+".", `<p>`+expected14+`.</p>`)
 	test(sha[:14]+",", `<p>`+expected14+`,</p>`)
 	test("["+sha[:14]+"]", `<p>[`+expected14+`]</p>`)
+
+	fileStrangeChars := util.URLJoin(repo, "src", "commit", "eeb243c3395e1921c5d90e73bd739827251fc99d", "path", "to", "file%20%23.txt")
+	test(fileStrangeChars, `<p><a href="`+fileStrangeChars+`" rel="nofollow"><code>eeb243c339/path/to/file #.txt</code></a></p>`)
 }
 
 func TestRender_CrossReferences(t *testing.T) {