opt: add resize area into the compatible ui mode

flutter/lib/desktop/pages/desktop_tab_page.dart

@@ -75,7 +75,7 @@ class _DesktopTabPageState extends State<DesktopTabPage> {
                 isClose: false,
               ),
             )));
-    return Platform.isMacOS
+    return Platform.isMacOS || kUseCompatibleUiMode
         ? tabWidget
         : Obx(
             () => DragToResizeArea(

flutter/lib/desktop/pages/file_manager_tab_page.dart

@@ -98,7 +98,7 @@ class _FileManagerTabPageState extends State<FileManagerTabPage> {
             labelGetter: DesktopTab.labelGetterAlias,
           )),
     );
-    return Platform.isMacOS
+    return Platform.isMacOS || kUseCompatibleUiMode
         ? tabWidget
         : SubWindowDragToResizeArea(
             child: tabWidget,

flutter/lib/desktop/pages/port_forward_tab_page.dart

@@ -107,7 +107,7 @@ class _PortForwardTabPageState extends State<PortForwardTabPage> {
             labelGetter: DesktopTab.labelGetterAlias,
           )),
     );
-    return Platform.isMacOS
+    return Platform.isMacOS || kUseCompatibleUiMode
         ? tabWidget
         : Obx(
           () => SubWindowDragToResizeArea(

flutter/lib/desktop/pages/remote_tab_page.dart

@@ -205,7 +205,7 @@ class _ConnectionTabPageState extends State<ConnectionTabPage> {
         ),
       ),
     );
-    return Platform.isMacOS
+    return Platform.isMacOS || kUseCompatibleUiMode
         ? tabWidget
         : Obx(() => SubWindowDragToResizeArea(
               key: contentKey,