Merge pull request #9097 from jcsp/wip-15866

mon: fix 'mon metadata' for lone monitors, and enable listing all metadata at once

Reviewed-by: Kefu Chai <kchai@redhat.com>

diff --cc qa/workunits/cephtool/test.sh
Simple merge

diff --cc src/mon/MDSMonitor.cc
Simple merge

diff --cc src/mon/MonCommands.h
Simple merge

diff --cc src/mon/Monitor.cc
Simple merge

diff --cc src/mon/Monitor.h
Simple merge

diff --cc src/mon/OSDMonitor.cc
Simple merge