languages: refactor

- No full restart requirement just reload
- Fix some systems not loading the language
- Fix RTL not applied if the lang was not set by the system

ks_includes/screen_panel.py

@@ -14,7 +14,6 @@ class ScreenPanel:
         self._screen = screen
         self._config = screen._config
         self._files = screen.files
-        self.lang = self._screen.lang
         self._printer = screen.printer
         self.labels = {}
         self._gtk = screen.gtk