SERVER-74200 is introducing a 2-phase notification protocol to describe the commit of a shardCollection request.

The protocol is planning to expand the existing schema for the shardCollection op entry, which is a user-visible event.

In order to maintain the existing contract between mongos and the clients of a nss/cluster.watch() command, the pipeline that feeds change stream events should be modified so that:

• only shardCollection events with phase: "commitSuccessful" | MISSING may reach the user
• the original schema of the op entry is applied (that is, the fields introduced by SERVER-74200 get removed).