(stream) Possible memory leak with new queue system

[tanguyvda]

When is not sent, the queue is not flushed. Next event is then put in the queue, and we still can't send the event because it fails. This goes on and on. THe queue table being bigger and bigger it leads to a memory leak.

two solutions

• completely drop the event (no broker retention, nothing in the queue)
• remove the event from the queue but keep it in broker retention meaning that we endlessly loop over it until the issue is fixed. (thus creating broker retention while we are looping on this event)