Make dry-run work with module methods having return types

[Naktibalda]

Closes #6463

[TavoNiievez]

ask for my review when you go to integrate to the 5.0 branch, I have a couple of suggestions for typing

[Naktibalda]

Now I think that it would be better to mock all methods of all modules to return correct types.

The main problem is that methods implemented in Tester classes are not steps, so they won't be mocked and they will call methods of real modules.

[Naktibalda]

I updated code to mock all modules method, so dry-run works as before, but methods return correct types.