ceph_filestore_dump: Add remove object command and usage for new commands

Signed-off-by: David Zafman <david.zafman@inktank.com>
ceph_filestore_dump: Add --type list to output objects in a pg in json
ceph_filestore_dump: Add list-attrs object command

Signed-off-by: David Zafman <david.zafman@inktank.com>
ceph_filestore_dump: Add list-omap object command

Signed-off-by: David Zafman <david.zafman@inktank.com>
ceph_filestore_dump: Add get-bytes object command

Signed-off-by: David Zafman <david.zafman@inktank.com>
ceph_filestore_dump: Add set-bytes object command

Signed-off-by: David Zafman <david.zafman@inktank.com>
ceph_filestore_dump: Add get-attr object command

Signed-off-by: David Zafman <david.zafman@inktank.com>