At the call site, we use the version, captured
in erm/token_metadata. In the handler, we use
double checking, apply_fence after the local
write guarantees that no mutations
succeed on coordinators if the fence version
has been updated on the replica during the write.
Fencing was also added to mutate_locally calls
on request coordinator, for the case
if this coordinator was isolated from the
topology change coordinator and missed the
barrier_and_drain command.
46f73fcaa6