SideBySideDiffEditor: Avoid code repetition

Change-Id: Ie49834a4896dbf32a87329345e52dc99ca2f86bd
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/diffeditor/diffenums.h

@@ -0,0 +1,14 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0+ OR GPL-3.0 WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+namespace DiffEditor {
+
+enum DiffSide {
+    LeftSide,
+    RightSide,
+    SideCount // Use only in array declarations
+};
+
+} // namespace DiffEditor