Adds Oracle ZFSSA driver for Manila

The driver allows Oracle ZFSSA to be a storage resource for Manila.
It uses the REST API to communicate with ZFSSA and perform the following:
* Create/delete NFS/CIFS shares.
* Create shares from snapshots.
* Create/delete snapshots.
* Allow/deny IP access to an NFS share.
* Get share status.

DocImpact
Change-Id: I2e4201842ee2fa2825bad3e14ff1615670a18d31
Implements: blueprint oracle-zfssa-driver
Merge "Adds Oracle ZFSSA driver for Manila"