Formalize CoreCoordinators

* Adds the CoreCoordinator interface
* Stores core coordinators in a separate list
* Includes CoreCoordinator details in NotifPipeline dump
* Makes DataStoreCoordinator and NotifLiveDataStore PipelineDumpable
* Make ListenerSet a Collection so that it can be dumped by PipelineDumper

Test: atest SystemUITests
Fixes: 208866714
Change-Id: I2e1d290f280514e2ab2b0571bbabc874c56c5197