Revert "JBIDE-16004: Update Forge2 Runtime to 2.0.0.Beta3"

This reverts commit 176e5058e53a3103c74e91c5cfcdcec21e64ca1b.
FORGE-1325: Eclipse plugin now uses UIExecutionContext
Removed unnecessary method
JBIDE-16166: Growl message does not appear or disappears prematurely