If a user manually creates a system.buckets.x collection, change streams has no way of distinguishing between this and a genuine buckets collection automatically created by a timeseries view.

Since we are implementing special handling for time series collections, this special handling will affect any system.buckets.x collections the user may have created, and result in incorrect change streams. We must prevent this case by ensuring this type of collection cannot exist.

SERVER-63126 disallowed creating a view on system.buckets. Now we need to disallow manually creating any system.buckets.x collection.

We also need to consider the case where there is already an existing system.buckets.x collection, manually created before this ticket was implemented. We should check for this situation and provide the user with a useful, actionable error message.