feat: Add Localization Manager

Created by: whitebear60

To add a new language to the app you need:

1. Create resources/de/griefed/resources/lang/lang_language code.lang file.
2. Add language code to the SUPPORTED_LANGUAGES list in Reference
3. Translate the app!

Please keep in mind that auto fallback to English when locale key doesn't exist in current language is not implemented yet. Now @Griefed need to replace all messages that he wants to be translatable with LocalizationManager.getLocalizedString(<translation key>) and, obviously, add this messages to lang_en_us.lang under translation keys that are exact the same as it mentioned in code.