Add machine commands "getnetlist", "getbridgelist"

[nilclass]

Add two new machine commands. These ones are used to query info from the Jumperless in a structured way.

• ::getnetlist[]: prints the netlist in a machine-readable way:

  ::netlist-begin
  ::net[1,1,GND,true,001c04,false,GND]
  ::net[2,2,5V,true,1c0702,false,+5V]
  ::net[3,3,3V3,true,1c0107,false,+3.3V]
  ::net[4,4,DAC_0,true,231111,false,DAC 0]
  ::net[5,5,DAC_1,true,230913,false,DAC 1]
  ::net[6,6,I_POS,true,232323,false,I Sense +]
  ::net[7,7,I_NEG,true,232323,false,I Sense -]
  ::netlist-end

• ::getbridgelist[]: prints the bridge list in the ::bridgelist[...] format