chore(project): merge class
feat(utils): add transformer utility

Related to CAM-207
fix(diagram export): add not null check

Test cases invoking the diagram export may raise a NPE because the
active BPMN editor may not be initialized.

Added a != null check to fix this.

Related to CAM-207
fix(compatibility): correctly handle dataObjects

Per BPMN 2.0 spec a dataObject must not be referenced in DI.
Instead it may be referenced by dataObjectReference that encapsulates
the visual representation of the object (similar to dataStores).

This commit fixes the wrong modeler behavior:

* DataObjectReferences get created for dataObjects newly added
  to the diagram
* import detects malformed dataObject constructs in BPMN 2.0 diagrams
  and fixes them by inserting a dataObjectReference

BREAKING CHANGE:

- Modeler creates DataObjectReferences (conforming with BPMN 2.0 spec)
  if new dataObjects are added to the diagram

Closes CAM-207
Merge branch 'CAM-207-data-object-reference' into develop