api functions protected by key, to control node

[thepiwo]

• add http api functions to control the node, e.g. start/stop miner
• protect the api using authorization header to match a key from config or environment

[cytadela8]

I think the private API should also have a separate server so it can be only accessible from localhost.

[thepiwo]

no, we want it to be accessible from remote as well, if the node provider wants to control a node running on a server. I think authorization token header is sufficient for security