Web fixes

lib/redux/document/document_actions.dart

@@ -436,7 +436,9 @@ void handleDocumentAction(
         final DocumentEntity? document =
             store.state.documentState.map[documentIds.first];
         if (kIsWeb) {
-          WebUtils.downloadBinaryFile(document!.name, document.data);
+          if (document?.data != null) {
+            WebUtils.downloadBinaryFile(document!.name, document.data!);
+          }
         } else {
           final directory = await (isDesktopOS()
               ? getDownloadsDirectory() as FutureOr<file.Directory>

lib/utils/web.dart

@@ -53,18 +53,18 @@ class WebUtils {
 
   static void reloadBrowser() => window.location.reload();
 
-  static void registerWebView(String html) {
+  static void registerWebView(String? html) {
     // ignore: undefined_prefixed_name
     ui.platformViewRegistry.registerViewFactory(
-        html,
+        html ?? '',
         (int viewId) => IFrameElement()
           ..src = html
           ..style.border = 'none');
   }
 
-  static void warnChanges(Store<AppState> store) {
+  static void warnChanges(Store<AppState>? store) {
     window.onBeforeUnload.listen((Event e) {
-      if (store.state.hasChanges()) {
+      if (store!.state.hasChanges()) {
         (e as BeforeUnloadEvent).returnValue =
             'Changes you made may not be saved.';
       }

lib/utils/web_stub.dart

@@ -18,7 +18,7 @@ class WebUtils {
 
   static void downloadTextFile(String filename, String data) {}
 
-  static void downloadBinaryFile(String filename, Uint8List? data) {}
+  static void downloadBinaryFile(String filename, Uint8List data) {}
 
   static void reloadBrowser() {}