Move ParsedRequest{} to gor/utils sub-package

This de-dupes the type definition used in both `listener` and `replay`.

utils/utils.go

@@ -0,0 +1,14 @@
+package utils
+
+import (
+	"fmt"
+)
+
+type ParsedRequest struct {
+	Timestamp int64
+	Request   []byte
+}
+
+func (self ParsedRequest) String() string {
+	return fmt.Sprintf("Request: %v, timestamp: %v", string(self.Request), self.Timestamp)
+}