Integrate ArchUnit tests

[igorwojda]

ArchUnit is a framework that allows to test app architecture. It looks like it's not suited for android, so some research, experimentation and potentially contribution to ArchUnit may be required to make it work with android project. https://github.com/TNG/ArchUnit/issues/241

Few tests that we could write with ArchUnit

• rule that protects boundaries between clean architecture layers - make sure that class defined in ...domain layer does not uses any classes from other layers (have imports from other layers).
• rule that verifies that every androidx.lifecycle.ViewModel child class has ViewModel suffix
• More Tests inspirations ...

ArchUnit User Guide