Clean up ComponentCreationContext tests. Add a couple test cases.

New test cases include a test to verify retrieving a definition from the server saves the def on the client for future requets and a test to verify creating a component with multiple levels of server dependencnies creates the cmp with a single XHR server request.

@rev byao@
@rev gtorres@
@bug W-1821211@
Merging origin/tbliss/master-pending-ComponentCreationContext-tests-round2 into master