Merge pull request #20343 from trociny/wip-rados-ordersnap

librados: add OPERATION_ORDERSNAP flag and yet another aio_operate method

Reviewed-by: Josh Durgin <jdurgin@redhat.com>

diff --cc src/include/rados/librados.h
Simple merge

diff --cc src/include/rados/librados.hpp
Simple merge

diff --cc src/librados/librados.cc
Simple merge

diff --cc src/test/librados_test_stub/LibradosTestStub.cc
Simple merge