Update Ganesha library to an "update access" style acces interface

The Ganesha library needs to be kept in sync with the driver access interface change (https://blueprints.launchpad.net/manila/+spec/new-share-access-driver-interface), in order to:

- maintain the seamless integration with drivers, providing an API to drivers to which they can easily delegate access related actions
- reap the benefits for Ganesha instrumentation logic in terms of not having to do an unconditional state reset/reconstruction on service startup as it was the case with the old access interface.