[514767] Provide preferences to configure comparison editor behavior

- Add preference for enabling the auto-selection of the first change
- Add preference for enabling the auto-highlight of related changes 
- Add preference for setting the default expansion level of the tree
- Move editor preference page to IDE UI (held no preferences previously)
- Consider preference settings in SMV accordingly
- Explicitly allow the creation of the NoSelectedItemViewer
- Avoid unnecessary updates when selection did not change

Bug: 514767
Change-Id: Iad7d26b3f3783e60268e8504add909151dc9cd5d
Signed-off-by: Martin Fleck <mfleck@eclipsesource.com>
13 files changed