Import Operations Log to update process instance state

Context:
If a running process instance (state:ACTIVE) that was already imported gets suspended, the suspended state is not set in Optimize. As the running instance importer already passed that particular instance and the completed instance importer is not catching this instance as it is still running.

AT:

• the user operationslog is imported in order to update running process instance states
  • we may consider filtering for suspend operations only
  • the running instance import should never override an already present state (assuming the operationslog went ahead of the running instance import it's state wins, so ACTIVE never overrides any other state)
  • the user operations log never overrides a completed state [COMPLETED, *_TERMINATED] it only updated from ACTIVE to SUSPENDED or vice versa
• the required engine permissions to read the user operations log are updated in the documentation on the engine user engines.${engineAlias}.authentication.user, we will need * auth for the user operationslog
  • this breaking change in terms of required authorizations is mentioned in the migration guide
• we document that users should always perform user operations on the REST API with user authentications to ensure the suspension state can be correctly imported (as otherwise no operations log entry is written) or otherwise set restrictUserOperationLogToAuthenticatedUsers=false in the connected engine to ensure an operation log is written also if there is no user authenticationContext for that particular request