Refactor localization system and migrate to Fyne's built-in support

Replaced the `i18n` and `toml` dependencies with Fyne's built-in language system for localization management. Updated the `Localizer` implementation to handle translations using JSON files and embed functionality. Simplified language selection and persisted settings via Fyne's preferences API.

kernel/error.go

@@ -2,14 +2,11 @@ package kernel
 
 import (
 	"fyne.io/fyne/v2"
-	"fyne.io/fyne/v2/app"
 	"fyne.io/fyne/v2/container"
 	"fyne.io/fyne/v2/widget"
 )
 
-func PanicErrorLang(err error, metadata *fyne.AppMetadata) {
-	app.SetMetadata(*metadata)
-	a := app.New()
+func panicErrorLang(a fyne.App, err error) {
 	window := a.NewWindow("GUI for FFmpeg")
 	window.SetContent(container.NewVBox(
 		widget.NewLabel("Произошла ошибка!"),