Fix E2EE files

lib/utils/matrix_file_extension.dart

@@ -0,0 +1,15 @@
+import 'dart:io';
+
+import 'package:famedlysdk/famedlysdk.dart';
+import 'package:open_file/open_file.dart';
+import 'package:path_provider/path_provider.dart';
+
+extension MatrixFileExtension on MatrixFile {
+  void open() async {
+    Directory tempDir = await getTemporaryDirectory();
+    final file = File(tempDir.path + "/" + path.split("/").last);
+    file.writeAsBytesSync(bytes);
+    await OpenFile.open(file.path);
+    return;
+  }
+}