[test] Workaround for Luna-specific behavior

It looks like starting from Luna, if an editor has a title starting with
a space, getTitle() will return a trimmed version without the leading
space. This can break some tests which expected the editor's title to
match the representation's name, when the sample data used for the test
create a name starting with a space (typically a diagram named " package
entities" because the sample ecore package used by the test has no
name).

Change-Id: Ifcafe5b779b11716b03b025cb446af1428ef9f83
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>
[cleanup] Make sure that ResourceDeltaVisitor does not cause
IllegalStateExceptions when analysing workspace deltas with possibly
disposed Resources
[435507] Specification for this issue

Bug: 435507
Change-Id: Ifceee32c530c86ee7d9246f6d85d8feec32f6673
Signed-off-by: Laurent Redor <laurent.redor@obeo.fr>