[InformationModeling] Add UML subset and apply UI simplifications Change-Id: Ie79d5a394f193a88885895c4c0434328cd89c20f Signed-off-by: Martin Fleck <mfleck@eclipsesource.com> Signed-off-by: Philip Langer <planger@eclipsesource.com> Also-by: Philip Langer <planger@eclipsesource.com>