fix: Add Go controller comment (google#280)

Author: duffn

go/database/sql/connection.go

@@ -101,6 +101,10 @@ func (conn *sqlCommenterConn) withComment(ctx context.Context, query string) str
 		commentsMap[core.Action] = ctx.Value(core.Action).(string)
 	}
 
+	if config.EnableController && (ctx.Value(core.Controller) != nil) {
+		commentsMap[core.Controller] = ctx.Value(core.Controller).(string)
+	}
+
 	// `driver` information should not be coming from framework.
 	// So, explicitly adding that here.
 	if config.EnableDBDriver {

go/database/sql/connection_test.go

@@ -147,7 +147,7 @@ func TestWithComment_WithContext(t *testing.T) {
 				},
 			),
 			query:     "SELECT 1;",
-			wantQuery: "SELECT 1/*action='any+action',application='app-1',db_driver='database%2Fsql%3Apostgres',framework='custom-golang',route='listData'*/;",
+			wantQuery: "SELECT 1/*action='any+action',application='app-1',controller='custom-controller',db_driver='database%2Fsql%3Apostgres',framework='custom-golang',route='listData'*/;",
 		},
 	}
 	for _, tc := range testCases {