Module naming/packaging

[stanbar]

We need to standardize the module naming and packaging. At the moment I hardcoded that the module must be in package io.raspberrywallet.modules

[PatrykMilewski]

can we make it like this:
io.raspberrywallet.modules.<module_name>

some modules are more than just one class, then having them as a package is good idea, to keep modules package away from chaos