Make better use of i18n (#20096)

* Prototyping

* Start work on creating offsets

* Modify tests

* Start prototyping with actual MPH

* Twiddle around

* Twiddle around comments

* Convert templates

* Fix external languages

* Fix latest translation

* Fix some test

* Tidy up code

* Use simple map

* go mod tidy

* Move back to data structure

- Uses less memory by creating for each language a map.

* Apply suggestions from code review

Co-authored-by: delvh <dev.lh@web.de>

* Add some comments

* Fix tests

* Try to fix tests

* Use en-US as defacto fallback

* Use correct slices

* refactor (#4)

* Remove TryTr, add log for missing translation key

* Refactor i18n

- Separate dev and production locale stores.
- Allow for live-reloading in dev mode.

Co-authored-by: zeripath <art27@cantab.net>

* Fix live-reloading & check for errors

* Make linter happy

* live-reload with periodic check (#5)

* Fix tests

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: zeripath <art27@cantab.net>

modules/markup/markdown/toc.go

@@ -9,7 +9,7 @@ import (
 	"net/url"
 
 	"code.gitea.io/gitea/modules/markup"
-	"code.gitea.io/gitea/modules/translation/i18n"
+	"code.gitea.io/gitea/modules/translation"
 
 	"github.com/yuin/goldmark/ast"
 )
@@ -18,7 +18,7 @@ func createTOCNode(toc []markup.Header, lang string) ast.Node {
 	details := NewDetails()
 	summary := NewSummary()
 
-	summary.AppendChild(summary, ast.NewString([]byte(i18n.Tr(lang, "toc"))))
+	summary.AppendChild(summary, ast.NewString([]byte(translation.NewLocale(lang).Tr("toc"))))
 	details.AppendChild(details, summary)
 	ul := ast.NewList('-')
 	details.AppendChild(details, ul)