Historic Process Instance missing fields: removalTime, rootProcessInstanceId & processDefinitionVersion

[StephenOTT]

https://docs.camunda.org/manual/7.15/reference/rest/history/process-instance/get-process-instance/

rootProcessInstanceId	String	The process instance id of the root process instance that initiated the process.

removalTime	String	The time after which the instance should be removed by the History Cleanup job. Default format* yyyy-MM-dd’T’HH:mm:ss.SSSZ.

processDefinitionVersion	Integer	The version of the process definition that this process instance belongs to.