Clean-up BTIF profile queue on profile shutdown

* Add btif_profile_cleanup(uuid) method to remove pending connection
  requests for individual UUIDs
* Call the above method in each profile's clean-up method
* Add unit tests for btif_profile_queue

Bug: 63790458
Test: make, unit tests, pair and connect car kits
Change-Id: I28288c295b7ca0259b2112c11b4e5a81d6f2e33c