Fix scrollwheel zooming issues by making scale factor much higher number

lib/screens/image_viewer_screen.dart

@@ -67,7 +67,7 @@ class ImageViewerScreen extends StatelessWidget {
                   clipBehavior: Clip.none,
                   constrained: true,
                   maxScale: 10.0,
-                  scaleFactor: 0.1,
+                  scaleFactor: 400,
                   child:
                       CachedNetworkImage(imageUrl: attachment.uri.toString()),
                 ),