Support localizing apphost (prompt and progress forms)

[Misiu]

Details

First of all, I'd like to say thank you for this amazing project 🎉🚀 It was so easy to set up everything and it just works!

I noticed that all the texts in installation prompt form are hardcoded in English. It would be useful if we could customize those texts and localize them. Not sure what would be the best way to do that, maybe store those strings in resources and use Ressy to alter them on build.