Add couchbase-cli support for hard reset of a node

Please see https://issues.couchbase.com/browse/DOC-11522

Can we add a cli command that permits hard reset of a particular node?
We must warn the user that this option should be exercised with caution because it wipes out all data on the node. They may want to create a backup before running this command.

It is intended only for use after an unsafe failover - to be able to add the node back to a cluster it was booted from.

The hard reset API:
curl -X POST -u Administrator:asdasd 127.0.0.1:9001/controller/hardResetNode
resets the node at 127.0.0.1:9001 such that all state - both config and data are lost.