Added Date & Time selectors in `Language & Currency" screen.
Added new properties in `local_app_settings` to set the date and time format.
Created all the chain from view to service to update date and time format.
Added date and time format functions in `Utils`.
Updated `FetchMoreMessagesButton`, `ChatTimePanel`, `AppSearch`, `TransactionBubbleView` and `TransactionDelegate` date and time text depending on the selected format.
Closes#5386
Igor Sirotin
Patryk Osmaczko
Noelia
Anthony Laibe