feat(ngMocks): cleanup $inject annotations after each test

this will help in detecting unannotated functions both in apps and angular core in case only part of the tests are run with strictDi
@lgalfaso I think I prefer to leave it as it is and do not make any assumptions about how `annotate` works just in order to save some cpu cycles... I think this is the most non-intrusive way, just listen to the calls and don't change any flows.