qa: exclude crimson from random-objectstore

qa: exclude crimson from random-objectstore

In rados/dashboard tests, random-objectstore is symlinked to
qa/objectstore. After #64715,
qa/objectstore also contains seastore as an objectstore.

To prevent seastore being used as an objectstore for
rados/dashboard tests, a new dir is created under qa/
which contains only crimson and seastore  specific yamls.

All other symlinks to crimson/seastore objectstore have
also been updated.

Fixes: https://tracker.ceph.com/issues/74052
Signed-off-by: Shraddha Agrawal <shraddhaag@ibm.com>