Implement First End Events to new marshallers (export only)

Parts of the task:

• Flatten the End Event properties
  • Flatten BPMNDefinition interface (name, documentation properties) required for all nodes at the same time to not break current interfaces and logic
    • "Full flattening" only for General Properties - name and documentation, others will be flattened only inside of their categories to preserve property categories in forms. Can be fully flattened in the future during/after full migration to the new forms engine.
  • Addition changes in non visible properties:
    • FontSet - removed
    • BackgroundSet - removed
    • CircleDimensionSet - removed
    • SimulationAttributeSet - preserved
• Marshaller for write only None End Event and Terminate End Event
  • Marshallers read will be done as part of
  • It's shape data (BPMNDiagram XML tag)
  • Properties: name, documentation, Metadata Attributes