Fix issues in Go proxy template
Fix issues in Go proxy template

* Do not insert comma between method args and return types
* Do not generate types/methods with same names
* Change the argument order in Caller.Call
* Refer to vrpc.Caller instead of defining a new interface type
* Do not define a type for map[string]interface{} to avoid name collision in a single package
* Define structs and interfaces with prefixed names

ChaosGroup/json-ws,ChaosGroup/json-ws,ChaosGroup/json-ws,ChaosGroup/json-ws,ChaosGroup/json-ws,ChaosGroup/json-ws