Moved fake manager creation and initial configuration into the proxy generator (Part I)

This is the first part of PR #372 (we split it up into 2 PRs as mentioned there).

It solves #371 partially, namely that the default behavior is available inside the c'tor call. Therefore it also solves the bug #368 (see the `when_faking_a_class_which_calls_virtual_property_members_in_constructor` test case).
I'm not sure we should be suppressing this message at the assembly level. I'd rather suppress it the type level until we decide it should be general rule for all interfaces in FIE. Indeed, the justification given here is just for one specific interface.