improve the topology watcher tests
improve the topology watcher tests

Using the newly added counters, add verification that the various
operation counts occur as expected.

This required also adding calls to topo.FixShardReplication in the
to avoid differences in the operation counts between the two types
of topology watchers.

Signed-off-by: Michael Demmer <4b836671cce77b1b2fbe63e5b2a1661879d8af44@slack-corp.com>

alainjobart/vitess,dcadevil/vitess,HubSpot/vitess,dcadevil/vitess,dcadevil/vitess,alainjobart/vitess,HubSpot/vitess,tinyspeck/vitess,vitessio/vitess,mahak/vitess,HubSpot/vitess,HubSpot/vitess,vitessio/vitess,enisoc/vitess,mahak/vitess,enisoc/vitess,HubSpot/vitess,tinyspeck/vitess,tinyspeck/vitess,dcadevil/vitess,enisoc/vitess,tinyspeck/vitess,enisoc/vitess,tinyspeck/vitess,davygeek/vitess,enisoc/vitess,alainjobart/vitess,davygeek/vitess,alainjobart/vitess,vitessio/vitess,mahak/vitess,vitessio/vitess,davygeek/vitess,mahak/vitess,mahak/vitess,alainjobart/vitess,vitessio/vitess,HubSpot/vitess,enisoc/vitess,davygeek/vitess,tinyspeck/vitess,davygeek/vitess,mahak/vitess,dcadevil/vitess,alainjobart/vitess,vitessio/vitess,alainjobart/vitess,dcadevil/vitess,vitessio/vitess,HubSpot/vitess,alainjobart/vitess,davygeek/vitess,enisoc/vitess,vitessio/vitess,tinyspeck/vitess,mahak/vitess,davygeek/vitess,dcadevil/vitess,HubSpot/vitess,mahak/vitess