test: Fix ceph_filestore_dump.sh test for new EC pool creation

Signed-off-by: David Zafman <david.zafman@inktank.com>
test: Reorg multi_stress_watch to prepare for ec option

If old options are specified maintain backward compatibility

Signed-off-by: David Zafman <david.zafman@inktank.com>
test: Add erasure coding to stress watch test

Fixes: #7438

Signed-off-by: David Zafman <david.zafman@inktank.com>
Merge pull request #1513 from ceph/wip-7438

Reviewed-by: Loic Dachary <loic@dachary.org>