Stunner - Perform rule evaluations before morphing an element

Before performing any morph operation, as the graph element is being updated with another BPMN (or whatever domain) bean, the labels/roles for the element are also being updated, it means the rules should be evaluated, against current context, but targeting the new bean (Definition) and its labels/roles.

These are the rules that should be evaluated:

• Check graph cardinality (cardinality)
• Check containment with current parent (containment)
• Check if nodes is docked to some parent as well (docking)
• check (children) docked nodes (docking)
• check children nodes (containment multiple)
• Check incoming connectors (connection/cardinality)
• Check outgoing connectors (connection/cardinality)

This ticket is related to a TODO on the code, see MorphNodeCommand::check method.