[Task] Add JFR events to Cryostat itself

[andrewazores]

Same as #461 , but for Cryostat 3.

Since #27 the same cryostat.jfc event template has been added to the container image, but this still references JFR events that are present in the old codebase and not the new one. Each of these event types in the Cryostat event template should be evaluated for either removal or having an equivalent JFR event added in the new codebase.