During FCV upgrade, DDL operations should start committing with UUIDs in kUpgrading as soon as the UUID is present. The first half of this requires the DDL coordinators to know whether or not the transitional feature flag is enabled or not. In 8.3+, this is easy because of the introduction of OFCV. However, for a coordinator which started in FCV 8.0, this needs to be done in the old style way where the feature flag is checked under a fixed fcv region and a field is persisted in the coordinator document.

This ticket is to introduce and set that field for unique shard IDs across all the coordinators. This should look similar to [the auth shards implementation|https://github.com/10gen/mongo/pull/53950].