Context:
To decouple the event import from the engine import config we should introduce dedicated configuration parameters for it.

AT:

• Remove Global Feature Flag (eventBasedProcess.enabled) and instead add
  • camunda activity event import switch per optimize instance (per engine)
  • Add Operational Feature Flag for Event Based Process Instance Import (processing of published event processes)
• the configuration documentation is updated accordingly
• the event based process technical documentation is updated accordingly
• the clustering documentation is updated to reflect event based import setup