For PM-2290, there is now a designated data shard (the catalog shard) that also serves as the CSRS for the cluster. An issue that we are running into is that commands that enter the catalog shard should be handled differently depending on whether or not the command was sent to the catalog shard because it is the CSRS or because it is a data shard.

Commands sent to the catalog shard are sent for one of two reasons. 1) Because it's the CSRS or 2) because it's a shard server. For the purpose of debugging we should annotate commands with this reason.