Fix build with fmtlib 8.1.1

Fix build with fmtlib 8.1.1

Bug: https://tracker.ceph.com/issues/53820
Bug-Debian: https://bugs.debian.org/1003469
Forwarded: no
Last-Update: 2022-01-14

+ changes in segment_manager.cc and segment_manager.h are backported from
  part of the large changes in https://github.com/ceph/ceph/commit/d5b0cd13
+ change in node_extent_accessor.h is not forwarded to upstream since it's
  a workaround. However it doesn't harm since it's just a error message
  which shouldn't happen anyway.

Gbp-Pq: Name fix-build-with-fmt-8.1.1.patch