Fix compatibility with JSON RPC

[davidyuk]

JSON-RPC specification doesn't say anything about version field in the root of response/requests objects. If it is needed to store protocol version it should use params, result, or method name to be compatible with JSON RPC.

I have seen the usage of version field in AEX-2 and AEX-5.

[shekhar-shubhendu]

@davidyuk we're trying to be as close to the state-channels JSON-RPC API which includes version field. you can find the example here.
The version field is as you guessed is needed to store protocol version.

[davidyuk]

Are AEX-2 and AEX-5 somehow connected to state-channels? If it is not, I think we can make a better decision here.

[shekhar-shubhendu]

it is not connected to but I would really like to keep the protocol version out of the method params as it does not makes sense to bind the version with the methods. If this breaks something we can find some other place to put it or we can remove it simply for now.

[shekhar-shubhendu]

@davidyuk on another thought and after discussing it with @nduchak we can do it this way:

wallet sends the supported version in the connection request (wallet.request.connect) only and if version mismatch or unsupported then SDK/aepp throws an error.