UI: Add paste source undo/redo actions

UI/data/locale/en-US.ini

@@ -309,6 +309,8 @@ Undo.MoveUp="Move '%1' up in '%2'"
 Undo.MoveDown="Move '%1' down in '%2'"
 Undo.MoveToTop="Move '%1' to top in '%2'"
 Undo.MoveToBottom="Move '%1' to bottom in '%2'"
+Undo.PasteSource="Paste Source(s) in '%1'"
+Undo.PasteSourceRef="Paste Source Reference(s) in '%1'"
 
 # transition name dialog
 TransitionNameDlg.Text="Please enter the name of the transition"

UI/window-basic-main.cpp

@@ -8385,6 +8385,11 @@ void OBSBasic::on_actionCopySource_triggered()
 
 void OBSBasic::on_actionPasteRef_triggered()
 {
+	OBSSource scene_source = GetCurrentSceneSource();
+	OBSData undo_data = BackupScene(scene_source);
+
+	undo_s.push_disabled();
+
 	for (auto &copyString : copyStrings) {
 		/* do not allow duplicate refs of the same group in the same scene */
 		OBSScene scene = GetCurrentScene();
@@ -8395,15 +8400,38 @@ void OBSBasic::on_actionPasteRef_triggered()
 						  false);
 		on_actionPasteTransform_triggered();
 	}
+
+	undo_s.pop_disabled();
+
+	QString action_name = QTStr("Undo.PasteSourceRef");
+	const char *scene_name = obs_source_get_name(scene_source);
+
+	OBSData redo_data = BackupScene(scene_source);
+	CreateSceneUndoRedoAction(action_name.arg(scene_name), undo_data,
+				  redo_data);
 }
 
 void OBSBasic::on_actionPasteDup_triggered()
 {
+	OBSSource scene_source = GetCurrentSceneSource();
+	OBSData undo_data = BackupScene(scene_source);
+
+	undo_s.push_disabled();
+
 	for (auto &copyString : copyStrings) {
 		OBSBasicSourceSelect::SourcePaste(copyString, copyVisible,
 						  true);
 		on_actionPasteTransform_triggered();
 	}
+
+	undo_s.pop_disabled();
+
+	QString action_name = QTStr("Undo.PasteSource");
+	const char *scene_name = obs_source_get_name(scene_source);
+
+	OBSData redo_data = BackupScene(scene_source);
+	CreateSceneUndoRedoAction(action_name.arg(scene_name), undo_data,
+				  redo_data);
 }
 
 void OBSBasic::AudioMixerCopyFilters()