mon/OSDMonitor: force op resend when pool overlay changes

mon/OSDMonitor: force op resend when pool overlay changes

If a client is sending a sequence of ops (say, a, b, c, d) and partway
through that sequence it receives an OSDMap update that changes the
overlay, the ops will get send to different pools, and the replies will
come back completely out of order.

To fix this, force a resend of all outstanding ops any time the overlay
changes.

Fixes: #8305
Signed-off-by: Sage Weil <sage@inktank.com>