feat: Enable native imaging for web

lib/utils/client_manager.dart

@@ -122,7 +122,8 @@ abstract class ClientManager {
         AuthenticationTypes.sso,
       },
       nativeImplementations: nativeImplementations,
-      customImageResizer: PlatformInfos.isMobile ? customImageResizer : null,
+      customImageResizer:
+          PlatformInfos.isMobile || kIsWeb ? customImageResizer : null,
       defaultNetworkRequestTimeout: const Duration(minutes: 30),
       enableDehydratedDevices: true,
       shareKeysWith: ShareKeysWith.values

lib/utils/custom_image_resizer.dart

@@ -18,12 +18,6 @@ import 'package:native_imaging/native_imaging.dart' as native;
 Future<MatrixImageFileResizedResponse?> customImageResizer(
   MatrixImageFileResizeArguments arguments,
 ) async {
-  if (kIsWeb) {
-    throw UnsupportedError(
-      'customImageResizer only supports non-web platforms.',
-    );
-  }
-
   await native.init();
 
   var imageBytes = arguments.bytes;