feat(fieldInjections): Extend properties panel

- add new tab to configure field injections for 'service task like' elements
-- support only field injections with child-elements in camunda modeler
-- ignore existing field injection configuration with attributes (no
process model changes)
- add testcases

related to #CAM-298
feat(parallel-GW/properties): Add async and exclusive

- add async and exclusive extension attribute to parallel gateway

related to #CAM-2225
fix(propertiesPanel/focus): Add fix to get focus

- fix multi page editor to get focus on properties panel with one click

related to #CAM-1922