added new format for json rpc call into conductor

[zippy]

• I have added a summary of my changes to the changelog

Adds a call route to the json rpc for the conductor for making zome calls.

The old way will still work, but is marked as deprecated, and will be removed in updates in the near future.

This means that instead of using

{"jsonrpc": "2.0", "id": "0", "method": "instance_id/zome/function", "params": {}}

to do the same thing, you would use

{
  "jsonrpc":  "2.0", 
  "id":  "0",
  "method":  "call",
  "params": {
     "instance_id" : "test-instance-1",
     "zome" : "greeter",
     "function" : "hello",
     "params": {}
  }
}

[maackle]

Just one small renaming request. And then the slightly larger discussion about id vs instance_id, but I would approve after disambiguating instances_map