qa: add ceph-rbd windows service restart test

qa: add ceph-rbd windows service restart test

We're adding a test that:

* maps a configurable number of images
* runs a specified test - we're reusing the ones from stress_test,
  making just a few minor changes to allow running the same test
  multiple times
* restarts the ceph-rbd Windows service
* waits for the images to be reconnected and refreshes the mount
  information
* reruns the test
* repeats the above workflow for a specified number of times,
  reusing the same images

This test ensures that:

* mounted images are still available after a service restart
* drive letters are retained
* the image content is retained
* there are no race conditions when connecting or disconnecting
  a large number of images in parallel
* the driver is capable of mapping a specified number of images
  simultaneously

Signed-off-by: Lucian Petrut <lpetrut@cloudbasesolutions.com>