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/items_to_convert.go

@@ -6,7 +6,6 @@ import (
 	"fyne.io/fyne/v2/container"
 	"fyne.io/fyne/v2/theme"
 	"fyne.io/fyne/v2/widget"
-	"github.com/nicksnyder/go-i18n/v2/i18n"
 )
 
 type ItemsToConvertContract interface {
@@ -35,21 +34,23 @@ func NewItemsToConvert(itemsContainer *fyne.Container, ffplayService FFplayContr
 
 	line := canvas.NewLine(theme.Color(theme.ColorNameFocus))
 	line.StrokeWidth = 5
-	checkboxAutoRemove := widget.NewCheck(localizerService.GetMessage(&i18n.LocalizeConfig{
-		MessageID: "autoClearAfterAddingToQueue",
-	}), func(checked bool) {
-		ItemsToConvert.isAutoRemove = checked
-	})
+	checkboxAutoRemove := widget.NewCheck(
+		localizerService.GetMessage("autoClearAfterAddingToQueue"),
+		func(checked bool) {
+			ItemsToConvert.isAutoRemove = checked
+		},
+	)
 	checkboxAutoRemove.SetChecked(ItemsToConvert.isAutoRemove)
 	localizerService.AddChangeCallback("autoClearAfterAddingToQueue", func(text string) {
 		checkboxAutoRemove.Text = text
 	})
 
-	buttonClear := widget.NewButton(localizerService.GetMessage(&i18n.LocalizeConfig{
-		MessageID: "clearAll",
-	}), func() {
-		ItemsToConvert.clear()
-	})
+	buttonClear := widget.NewButton(
+		localizerService.GetMessage("clearAll"),
+		func() {
+			ItemsToConvert.clear()
+		},
+	)
 	buttonClear.Importance = widget.DangerImportance
 	localizerService.AddChangeCallback("clearAll", func(text string) {
 		buttonClear.Text = text