qa/suites/crimson-rados-experimental: Test recovery thrash test

https://tracker.ceph.com/issues/67446 is merged, We should be able
to start testing Seastore similar to `crimson-rados/thrash` suite which
uses ceph_test_rados and rados bench.
crimson-rados-experimental is a copy of crimson-rados thrash with only
objectstore changes.
Once the experimental suite is ready, we could add seastore to
crimson-rados/thrash and remove crimson-rados/thrash_seastore_* variants.

See: https://tracker.ceph.com/issues/71237

Signed-off-by: Matan Breizman <[email protected]>

Author: Matan-B

qa/suites/crimson-rados-experimental/thrash/clusters/crimson-fixed-2.yaml

@@ -0,0 +1 @@
+.qa/clusters/crimson/crimson-fixed-2.yaml

qa/suites/crimson-rados-experimental/thrash/clusters/fixed-2.yaml

@@ -0,0 +1 @@
+.qa/objectstore/crimson/seastore

qa/suites/crimson-rados-experimental/thrash/objectstore/.qa

@@ -32,3 +32,4 @@ tasks:
     chance_inject_pause_short: 0
     chance_thrash_cluster_full: 0
     chance_reset_purged_snaps_last: 0
+    chance_trim_stale_osdmaps: 0