+str #15091 Add time driven operators

* TimerTransformer with support for named timers
* dropWithin
* takeWithin
* groupedWithin
=pro silence github tagging (curl)
Merge pull request #15311 from ktoso/pro-silence-curl-2-3-dev

=pro silence github tagging curl (pr validation)
Merge pull request #15245 from akka/wip-15091-stream-time-driven-patriknw

+str #15091 Add time driven operators
+str #15218 Add mapFuture operator