Prevent recv / getEvent conflicts in the DB notification map

[maxdml]

If a workflow receives on a topic, and other workflows get event from that workflow on a key that is equal to the topic, it is possible for the recv() workflow to fail the receive, because of a key collision in the notification maps.

[tuannguyensn2001]

hi @maxdml , i would like to work on this issue

[maxdml]

Thanks @tuannguyensn2001 . For this the solution would simply be using two maps