Optimize performance of IncludeMemberByPathSelectionRule

[jnyrup]

This PR has three parts:

• Lazy-loading Segments instead of eagerly in constructor
• Caching segments for candidates, by wrapping them as a MemberPath
• Use type check as fail-fast in IsSameAs

[dennisdoomen]

What are you trying to accomplish with this PR?

[jnyrup]

It triggered me that:

• the candidate memberpath was segmentized 1-3 times in IncludeMemberByPathSelectionRule, while we can do with atmost 1
• segments were eagerly computed, where I prefer to minimize the work in the constructor
• the segments were (to me) unnecessarily copied into a List.
• the candidate memberpath was segmentized before the declaringTypes are compared.

I think IncludeMemberByPathSelectionRule becomes prettier