THRIFT-4285 Move TX/RX methods from gen. code to library

This change removes a lot of duplication from generated code and allows
the caller to customize how they can read from / write to the
transport.  Backwards compatible adapters make the change compatible
with existing code in use by consuming applications.

Client: Go

This closes #1382
diff --git a/lib/go/test/tests/protocol_mock.go b/lib/go/test/tests/protocol_mock.go
index 9197fed..8476c86 100644
--- a/lib/go/test/tests/protocol_mock.go
+++ b/lib/go/test/tests/protocol_mock.go
@@ -24,6 +24,7 @@
 
 import (
 	thrift "thrift"
+
 	gomock "github.com/golang/mock/gomock"
 )