[mre] Calculate Avg Talk Time in MRE

MRE should get Average Talk Time of every queue upon startup, from Reporting Connector (CSN-1159). Mre will calculate average talk time upon every task end and update Average Talk Time of respective Queue.
Average Talk Time Calculation:

Average Talk Time = (Average Talk Time + Current Task Handling Time ) / 2

Above describe formula doesn't yield true results usually. For more information see this discussion.

ramzan.shah implement it according to formula described here.