TimeLock Can Be A Client To TimeLock

[jeremyk-91]

In PDS-93832, we observe that TimeLock is able to get into a state where nodes are able to exchange pings, but clients are unable to actually have any client requests serviced.

It may be possible for TimeLock itself to identify that it has gotten into this state, and then recover through the abdication mechanism in #4058 (provided of course that the errant leader can recognise this).