Merge pull request #23743 from trociny/wip-rbd-config-pool

librbd: pool and image level config overrides

Reviewed-by: Jason Dillaman <dillaman@redhat.com>

diff --cc src/common/config_proxy.h
Simple merge

diff --cc src/librbd/Operations.cc
Simple merge

diff --cc src/librbd/image/RefreshRequest.cc
Simple merge

diff --cc src/test/librbd/image/test_mock_RefreshRequest.cc
Simple merge