vdpa_sim_blk: backport latests features [rhel-9.2.0]

Bugzilla: https://bugzilla.redhat.com/2136818

Depends: https://bugzilla.redhat.com/2133164

We are in the process of adding support for vdpa-blk in QEMU via libblkio.

To test it, we need the latest features implemented upstream (flush, discard, write-zeroes) in the vDPA block simulator.

So let's backport the latest changes and dependencies, including vringh changes since it is used by the simulator.

Let's apply on top of !1500 (merged) to avoid conflicts.

Signed-off-by: Stefano Garzarella sgarzare@redhat.com