Use MSPV2_SET_SETTING to set small_angle to 180 on FW presets

- Add a json file with the types of all settings, generated by
the settings generator on INAV.
- Implement MSPV2_SETTING and MSPV2_SET_SETTING, which gives us
access to any value exposed via settings.
- Use this to set small_angle to 180 in FW presets.

js/msp.js

@@ -283,6 +283,7 @@ var MSP = {
 
         switch (this.protocolVersion) {
             case this.constants.PROTOCOL_V1:
+                // TODO: Error if code is < 255 and MSPv1 is requested
                 length = payloadLength + 6;
                 buffer = new ArrayBuffer(length);
                 view = new Uint8Array(buffer);