Split ResolverImpl

ResolverImpl currently contains about 2300 lines of code. That is way too big for a single class.

I looked into it and found that the checkDynamicPackageSpaceConsistency and checkPackageSpaceConsistency methods and their dependent methods form a nice subset. I would move that into a class ConsistencyCheck.

Both would share all of the inner classes of ResolverImpl but nothing else.
So I think i would make sense to move these inner classes to separate files.

These changes should nicely split the classes into
ResolverImpl : 1400 lines
ConsistencyCheck : 600 lines