Draft: 0000 u introduce customexception

Description

Introduce CustomException class to have a generic exception class.

Unfortunately, AppLounge code does not respect Open-Closed principle so we still have to deal with a member called "type" in this class.

The idea is to get rid off this "type" member and probably also the "user" member.

Screenshots

Technical details

Tests

Issues

10 commandments of code reviews

👪 ❤ https://gitlab.e.foundation/internal/wiki/-/wikis/mobile-team/guidelines/Code-review