tools, test, osd, osdc, librados: Implement pgls of all namespaces

Add rados --all option for ls to output all namespaces
Add rados --default option to cancel --all when in CEPH_ARGS environment
Keep librados and pg_ls_response_t over the wire backwards compatibility
Add assert to old librados interfaces that ANY_NSPACE is NOT allowed
Add release note

Fixes: #9031

Signed-off-by: David Zafman <dzafman@redhat.com>