Fix FakeDbSet to be ok with collections that haven't been explicitly initialized.
Update BackendFacts to xunit 1.9.2 so we don't get multiple xunit package versions restored which appears to be bad for build.
Clean up tests further by making it Fakes.User instead of Fakes.User.User and cleaning up the slightly weirdly underutilized constructor on User.
Dont do noisy tracing when its not a big deal.
Merge pull request #1587 from NuGet/tilovell/cleanupcleanuptests

Tilovell/cleanupcleanuptests