Junction types shouldn't expose UI features in DiagramModelArchimateObject
[FormatPainterTool] Ensure all Junction types are not paintable
Remove IEditorLabelProvider extension handler and use IElementUIProvider handler

* IEditorLabelProvider extension handler removed
* IElementUIProvider extension handler added
* Improve and refactor all IElementUIProvider instances
* Add more IElementUIProvider instances to fill in the missing parts
* IElementUIProvider instances are declared as extensions in plugin.xml
* Remove IElementUIProvider#getDefaultShortName()
* Refactor and inprove EditPartFactory instances (Archimate, Sketch & Canvas)
* Remove the rubbish from ArchimateLabelProvider