LEAH-1937: UI: Translation
- Removed not used NoCANBUS development settings.
- Added the two systemLocale and systemLanguage in the Settings singleton class, to be accessed by _Setting in one place.
- Renamed the isValid method in the Settings class to exists for clarity.
- Added local to the filename method in Settings to get the setting file name with the defined locale.
- Made the Category of the settings order to set eSettingsSystem at top, to get the locale first and then read the rest of the settings files according that setting.
- Separated the parse section from the read method to simplify the read function.
- Two big logic in Settings::read has changed:
1. the read won't read any conf file in the settings path anymore, since the order is not important and each file existance.
2. the Settings::read now reads a file and parse it after in oppose to read all files and the parse them. That is mainly because we need to make decision base on the content of the setting files (System.conf in this case for now)
- Renamed the Settings::save to saveSystem for clarification, since that is the only writable setting, and that does not have locale too.
