Some tweaks for macOS target (#1260)

* fix macOS save video cover

* not hide title bar for macOS

lib/main.dart

@@ -78,14 +78,12 @@ void main() async {
     );
   } else if (Utils.isDesktop) {
     await windowManager.ensureInitialized();
-    WindowOptions windowOptions = WindowOptions(
-      minimumSize: const Size(400, 720),
-      size: const Size(1180, 720),
+    WindowOptions windowOptions = const WindowOptions(
+      minimumSize: Size(400, 720),
+      size: Size(1180, 720),
       center: true,
       skipTaskbar: false,
-      titleBarStyle: Platform.isMacOS
-          ? TitleBarStyle.hidden
-          : TitleBarStyle.normal,
+      titleBarStyle: TitleBarStyle.normal,
       title: Constants.appName,
     );
     windowManager.waitUntilReadyToShow(windowOptions, () async {

macos/Runner/DebugProfile.entitlements

@@ -10,5 +10,7 @@
 	<true/>
 	<key>com.apple.security.network.client</key>
 	<true/>
+	<key>com.apple.security.files.user-selected.read-write</key>
+    <true/>
 </dict>
 </plist>

macos/Runner/Release.entitlements

@@ -6,5 +6,7 @@
 	<true/>
 	<key>com.apple.security.network.client</key>
 	<true/>
+	<key>com.apple.security.files.user-selected.read-write</key>
+    <true/>
 </dict>
 </plist>