When adding many objects(10.000+) via python at once, the notifier queue
becomes very large. Measured with hotspot, this duplication check takes a
huge amount of time.
{F13397122}
This (draft) prototype adds a hashmap for looking up duplicates. Using this
hashmap i.o. the listbase for duplication check speedups the performance greatly.
{F13397123}
This patch is a draft, meant to discuss the solution of using a different, more
robust datatype, for duplication check.
It misses implementation of deleting/removing notifications and adding events.