Integrate sync beacon (#670)

* Use sync beacon follower plugin instead of sync plugin

* Remove sync and bootstrap plugin

* Refactor sync beacon stuff

* Update Docker network to use sync beacon plugins

*  Add detailed sync status to dashboard

*  Add detailed sync status to info API

*  Fix linter warning

*  Add Explorer support for sync beacon messages

* Initial integration test support for sync beacon plugins

* Fix consensus integration test

* Disable sync beacon follower plugin according to config

*  Fix dRNG integration-test

* Fix sync beacon test

* 

 Fix common integration test

* Clean up and add some comments

Co-authored-by: capossele <angelocapossele@gmail.com>