BatonView doesn't need to deal with UserMessage objects, as ApplicationWorkbenchAdvisor handles them
GDA-5329 Handle BatonRequested events in ApplicationWorkbenchAdvisor, not in BatonView

Handling them in BatonView means the view needs to have been opened for the
events to be handled.
Merge branch '8.34' of
ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-core.git into 8.34

Conflicts:
	uk.ac.gda.client/src/gda/rcp/ApplicationWorkbenchAdvisor.java