Mint RPC Server

[thesimplekid]

We would like to add an RPC server to the mint so that a mint operator has both better control of mint settings with the ability to change these settings without restarting and changing the config file as currently required. This should also include methods that give the mint operator better visibility into their mint operator in order to better mange their mint and lightning liquidity,

Below is list of methods that I think should be supported.

MInt

• Update NUT06 info description etc
• Rotate keyset
• View total issued ecash
• View total spent ecash
• View total outstanding (difference of the above two)
• Issued, spent and outstanding per keyset
• Disable/Enable mint and melt

Lightning

• Open channel
• Close channel
• Balance view

cc: @davidcaseria @crodas