Remember input language by app

[markokocic]

It would be nice if HeliBoard would remember last used input language not globally, but based on an app.

Use case: I have 5-6 different languages installed. I use browser and terminal almost exclusively in English, messengers in my native language, bank apps in German and language learning apps in the language I learn.

It would be very nice, if possible, if HeliBoard would remember last used language for every app when started, so I wouldn't need to switch keyboard every time when switching app.