fdb-kubernetes-monitor delay shutdown

[johscheuer]

What would you like to be added/changed?

There are cases where it could be useful for the new fdb-kubernetes-monitor to delay the shutdown of its own process but shutting down the fdbserver processes when receiving a shutdown signal. This should be optional with the option to opt-out of this configuration. Shutting down the fdbserver processes but not the monitor itself has the benefit that the Pod will be stuck in the terminating state for the defined grace period (30 seconds) but the fdbserver process(es) will be shut down, giving the FDB cluster controller the opportunity to better react on the down processes.

[johscheuer]

Implemented in: https://github.com/apple/foundationdb/pull/11108 we have to add support for this in the operator