* Improve the ping endpoint so that it can optionally check for leader agreement across all meta servers
* Add Ping method to the meta client
* Fix ClusterID tests
* Remove WaitForLeader from meta client and remove unnecessary references to it
* increase sleep on error in client exec in case a server went down so we don't max out retries before a new leader gets elected
* update and add close logic to service, handler, raft state, and the client
* Add dir, hostname, and bind address to top level config since it applies to services other than meta
* Add enabled flags to example toml for data and meta services
* Wire up add/remove raft peers and meta servers to meta service
* Update DROP SERVER to be either DROP META SERVER or DROP DATA SERVER
* Bring over statement executor from old meta package
* Start meta service client implementation
* Update meta service test to use the client
* Wire up node ID/meta server storage information