CONTROLLER-2053 deprecates ask-based protocol, this is a follow-up to remove it from configuration and code base.
This issue covers the bits around:
- DistributedDataStore, i.e. the frontend, which need to be removed
- Shard (and ShardCommitCoordinator, messages, etc.) are part of the backend and need to be deprecated for removal
- Shard should issue a stern warning when it encounters ask-based protocol.
A follow up issue will remove the backend bits in the next major release.