Cleanup the attestation tracker (#4584)

* Add assertions for the head and finality

* Remove duplicate tests form beacon-node package

* Fix the order of assertions

* Remove a debug logging

* Fix assertions

* Fix attestation issue for slot 16

* Update number of epochs for tests

* Remove debug logging

* Add sync committee assertions

* Remove unused import

* Update epoch sync participation

* Cleanup the attestation tracker

* Fix the lint error

* Update the code as per feedback

* Rename version to fork