CallSiteValidator doesn't cache results of the walk

[davidfowl]

When ScopeValidation is on for the dependency injection container, we walk to resolution graph and find places where service lifetimes are mismatched (like singleton -> scoped). This logic currently doesn't mark visited services which leads to re-calculating results repeatedly which ends up being O(N!).

Run this example with scope validation on:
https://github.com/sergey-kolodiy/AspNetCore.DI

[ghost]

As part of the migration of components from dotnet/extensions to dotnet/runtime (aspnet/Announcements#411) we will be bulk closing some of the older issues. If you are still interested in having this issue addressed, just comment and the issue will be automatically reactivated (even if you aren't the author). When you do that, I'll page the team to come take a look. If you've moved on or workaround the issue and no longer need this change, just ignore this and the issue will be closed in 7 days.

If you know that the issue affects a package that has moved to a different repo, please consider re-opening the issue in that repo. If you're unsure, that's OK, someone from the team can help!