LPS-48895 add RepositoryEventTriggerCapability to all repos

If a repository doesn't define a RepositoryEventTriggerCapability, wire
in the Liferay implementation.

If a repository defines the capability, but doesn't expose it, leave it
as it is.
LPS-48895 no need to copy collections

New capability collections are created for each repository instance
inside the RepositoryInstanceDefinition.
LPS-48895 extract common code
LPS-48895 rename variables

Repository instances aren't necessarily external.