AT:

• it is possible to create a HistoricActivityInstanceQuery: `historyService.createHistoricActivityQuery()`
• it is possible to query after:
• per default it filters after the number of unfinished activity instances
• `historicActivityInstanceQuery.includeFinished()`: includes the number of finished activity instances
• `historicActivityInstanceQuery.includeCanceled()`: includes the number of canceled activity instances
• `historicActivityInstanceQuery.includeCompleteScope()`: includes the number of activity instances, which completes a scope (ie. consumes a token and does not produce a new token)
• returns a statistic which contain the following attributes:
• `activityId`: the activity id
• `instances`: the number of all unfinished activity instances of the activity
• `finished`: the number of all finished activity instances of the activity
• `canceled`: the number of all canceled activity instances of the activity
• `completeScope`: the number of all activity instances which completes a scope