Automatic merge from submit-queue (batch tested with PRs 45374, 44537, 45739, 44474, 45888)

[Federation] Refactor sync controller's reconcile method for maintainability

This PR refactors the sync controllers reconcile method for maintainability with the goal of eliminating the need for type-specific controller unit tests.  The unit test coverage for reconcile is not complete, but I think it's a good start.

cc: @kubernetes/sig-federation-pr-reviews