add support for multiple activity ids when building query for external tasks
In Cockpit I can see details on external tasks
Philipp Ossler can review this when you are done ...
Mariusz Sielski, we don't need sorting by activityId for now, right?
Svetlana Dorokhova I am only sorting by timestamp right now
Philipp Ossler, please review the changes.
Mariusz Sielski, please try to send an array instead of a string.
Philipp Ossler, docs for two count requests are updated.