mon: clear connection score during update & add sanity check live/dead connection...

mon: clear connection score during update & add sanity check live/dead connection report

When upgrading the monitors (include booting up),
we check if `peer_tracker` is dirty or not. If
so, we clear it. Added some functions in `Elector` and
`ConnectionTracker` class to
check for clean `peer_tracker`.

Moreover, there could be some cases where due
to startup weirdness or abnormal circumstances,
we might get a report from our own rank. Therefore,
it doesn't hurt to add a sanity check in
`ConnectionTracker::report_live_connection` and
`ConnectionTracker::report_dead_connection`.

Fixes: https://tracker.ceph.com/issues/58049
Signed-off-by: Kamoltat <ksirivad@redhat.com>