Implemented Proper Protocol Composition Type Parsing

[art-divin]

Resolves #815

Context

Currently Sourcery does not properly parse types which are declared as a combination of a class and protocol.

1 protocol P {}
2 class C {}
3 class B: C {}
4 class A: C & P {}

here in this example, type A would not have C or P in its implements, inherits, based collections.

This PR adds this possibility for accessing types if the declaration is combining them, but also, this PR removes all Class instances from implements when such combination of Class & Protocol is used in the type declaration.
This behaviour is different from how it was working before, where Class instances were put into implements after parsing ProtocolComposition, which was against the documentation and common sense.