To support FCV transitions with a catalog shard, we need to ensure that:

• A catalog shard does not send duplicate "phase-x" commands to shards"
• We update any "if statements" that involve a clusterRole to also be able to differentiate between a catalog shard acting as a config server or as a shard (this includes the ones in the hooks and ones outside of the hooks)
• The FCV document doesn't get updated a duplicate amount of times

Note that this can only be worked on once the 7.0 is out, otherwise FCV upgrades/downgrades are not possible.