- the test now waits for specific set of log messages rather than wait for
timeout looking for just one message.
- we don't wanna sample the current length of the log after an action, due
to a race, we need to start the search from the line number of the last
message we where waiting for.
- when attempting to trigger a full sync, use multi-exec to avoid a race
where the replica manages to re-connect before we completed the set of
actions that should force a full sync.
- fix verify_log_message which was broken and unused
tests were sensitive to additional log lines appearing in the log
causing the search to come empty handed.
instead of just looking for the n last log lines, capture the log lines
before performing the action, and then search from that offset.
