Add node detector blacklist api

[Niklp09]

Useful for mods which register "airlike" nodes, e.g. wielded_light for invisible light nodes.

[SmallJoker]

1. The name is misleading. It only backlists nodes in case no node name is specified by the player. I'd expect blacklists to apply in all cases. I'd suggest to rename it to "airlike" or "empty" nodes.
2. Might it make sense to generally ignore all nodes with def.drawtype == "airlike" and not def.drowning for simplicity? That would automatically cover wielded_light.

[Niklp09]

It only backlists nodes in case no node name is specified by the player.

Do you think it's better to ignore (blacklisted) nodes when they're specified? I left this since it's maybe helpful for some players :thinking: .

Edit: (expecting automatic node blacklisting) mesecons_random:ghoststone_active is a canidate which players might want to detect.

Might it make sense to generally ignore all nodes with def.drawtype == "airlike" and not def.drowning for simplicity?

I'll add this.