Add: GetInterface for rpc_service.go

common/rpc_service.go

common/rpc_service_test.go

config/config_loader.go

config/config_loader_test.go

config/service_config.go

filter/filter_impl/generic_service_filter_test.go

protocol/dubbo/client_test.go

protocol/dubbo/dubbo_exporter.go

protocol/grpc/grpc_exporter.go

protocol/jsonrpc/http_test.go

protocol/jsonrpc/jsonrpc_exporter.go

protocol/jsonrpc/jsonrpc_invoker_test.go

protocol/rest/rest_exporter.go

protocol/rest/rest_invoker_test.go

protocol/rest/rest_protocol_test.go