Stop flush should be invoked by cluster members individually when flush coordinator leaves

Currently when member A who is a coordinator leaves we execute flush coordinator transfer. That is member A starts flush for view V but member B completes it with stop flush.

Member B, neighbor of A, receives a view V where coordinator is excluded, it takes over completion of flush. However, when B sends stop flush, then stop flush might arrive at member C before view V sent by A. Thus events get reordered.

If each remaining member in V detects (through view) that member A left then each one of the members can complete flush individually by "pretending" that it received stop flush from A.

This bug is likely to occur only with bundling disabled.