fix(util): infinite loop in getDiagram method
fix(properties): suppress "disposed" warning in properties panel
feat(scroll padding): initial work for scroll padding

this is the initial work for the scroll padding, atm it seems the only
way is to create a invisible rectangle with the bounds of the diagram
+ padding, the bounds of this rectangle need to be calculated initially
and updated on moves, currently this is hooked into the BPMN DI shape
update
chore(imports): organize imports
feat(scroll padding): implemented brilliant idea of brogrammer nico

we are now using a small 1px rectangle in the bottom right corner
which will increase the scrollbar scale (instead of using a rectangle
with full diagram dimensions), position of this small rect is still
updated during BPMN DI update. this solves problems like ctrl+a
and leaves move / create logic untouched.
feat(scroll padding): fix tests
feat(scroll canvas): complete work on scroll shape

mainly refactoring and move of funcionality but also
steamlining of associated utilities
Merge remote-tracking branch 'remotes/origin/scrollext' into develop

Conflicts:

org.eclipse.bpmn2.modeler.core/src/org/eclipse/bpmn2/modeler/core/features/DefaultMoveBPMNShapeFeature.java

org.eclipse.bpmn2.modeler.core/src/org/eclipse/bpmn2/modeler/core/layout/util/LayoutUtil.java

org.eclipse.bpmn2.modeler.core/src/org/eclipse/bpmn2/modeler/core/utils/BusinessObjectUtil.java

org.eclipse.bpmn2.modeler.core/src/org/eclipse/bpmn2/modeler/ui/features/participant/CreateParticipantFeature.java