Mining RPC commands / code is excluded from release builds due to the fact that most antivirus software flags mining software and it doesn't make sense to mine on mainnet. However, some people will use these binaries on testnet / regtest and will be confused when mining rpcs don't work.

As such, if mining code isn't compiled in, then an error should be thrown when a user runs a mining rpc comm

A user recently ran into trouble where they set up a new service node but had lokinet & SS misconfigured, and almost immediately got deregistered as a result.

We can detect this, though, and make the prepare_registration command fail if the SN hasn't received SS/lokinet pings yet.

The command could also add a "+force" option that lets it prepare even without having received pings (in which c