Historically we've been able to tell if the mock is running or not from server code via checking if the host params for the search index management host are not set. However, it has become clear that the mongot mock doesn't set every node with a searchIndexManagementHost param. Therefore we cannot rely on globalSearchIndexParams.host.empty() to filter out index commands from mock tests

To correct this, the mongotmock + sharding test infrastructure will need to make sure that option to launch a search index management host

We're going to move the call to replicateSearchIndex from production code to javascript. To do this we have to add a new command, ClusterReplicateSearchIndexCommand