fix: keep window pos after new conn (#8834)

1. Keep window pos
2. Do some init in StatefulWidget constructor.
If try init in its state class, it may be too late. Because I see the
init function is called after building the widget tree.

Signed-off-by: fufesou <linlong1266@gmail.com>

flutter/lib/desktop/pages/remote_tab_page.dart

@@ -407,12 +407,14 @@ class _ConnectionTabPageState extends State<ConnectionTabPage> {
       final display = args['display'];
       final displays = args['displays'];
       final screenRect = parseParamScreenRect(args);
+      final prePeerCount = tabController.length;
       Future.delayed(Duration.zero, () async {
         if (stateGlobal.fullscreen.isTrue) {
           await WindowController.fromWindowId(windowId()).setFullscreen(false);
           stateGlobal.setFullscreen(false, procWnd: false);
         }
-        await setNewConnectWindowFrame(windowId(), id!, display, screenRect);
+        await setNewConnectWindowFrame(
+            windowId(), id!, prePeerCount, display, screenRect);
         Future.delayed(Duration(milliseconds: isWindows ? 100 : 0), () async {
           await windowOnTop(windowId());
         });