Delete notification (also known as trim or unmap) is a feature that
notifies the underlying storage devices that data blocks are no longer
in use so they can be freed.
Implements: blueprint delete-notifications
Co-Authored-By: Micu Matei-Marius <mmicu@cloudbasesolutions.com>
Change-Id: I2a1670f921fce1165df48096c6fde8660b21282e