Nakamoto Miner[3.0] - Make mock-mining config parameter hot-swappable

[obycode]

Is your feature request related to a problem? Please describe. It would be nice to be able to switch between mock mining and real mining without a restart.

Describe the solution you'd like Most of the other parameters in the configuration are hot-swappable. It would be nice if the mock-mining parameter was as well.

Describe alternatives you've considered The alternative is to restart the node.

Additional context This has surprised people multiple times.