[FAB-12029] fix TestAddAndRemove flakes
[FAB-12029] fix TestAddAndRemove flakes

Adjust pull engine timeouts and fix mocked membership to not return
self.

Change-Id: I69246a96c1369cb97a92f36e313f84405a71221e
Signed-off-by: Artem Barger <6d127d713cb520aa658cf81ac2373d74ffc1958c@il.ibm.com>

hyperledger/fabric,stemlending/fabric,stemlending/fabric,muralisrini/fabric,binhn/fabric,manish-sethi/fabric-sidedb,stemlending/fabric,manish-sethi/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,jimthematrix/fabric,binhn/fabric,muralisrini/fabric,manish-sethi/fabric,binhn/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,hyperledger/fabric,muralisrini/fabric,stemlending/fabric,jimthematrix/fabric,manish-sethi/fabric-sidedb