qa/suites/crimson-rados: update clusters dir

qa/suites/crimson-rados: update clusters dir

* Introduce qa/clusters/crimson
  4 deployment clusters (1/2/3/4 nodes) options same as classic.

* Symlink all cluster dirs to the common dir above
  For now keep using only 1/2, we could add 3/4 later on.

* Move to "crimson cpu num" instead of specifying
  "crimson cpu set" set.
  - We expect users to mostly use this option for deploying
    clusters, so use this as testing default.

* remove "crimson bluestore cpu set" which is responsible for
  cpu pinning exclusiveness in seastar/alien cores.

* ignore "for optimal performance" cluster warning now that we
  no longer pin cpus for testing.

Signed-off-by: Matan Breizman <mbreizma@redhat.com>