[pointer_interceptor] fix width and height unset warning on web platform (flutter#5864)

This PR adds width/height to the dom element created by the default factory to prevent the framework from screaming at usages of this plugin.

Needed until this bit becomes `stable`:

* https://github.com/flutter/engine/blob/3106e08e12198d98b75c459ac3290f4101b68574/lib/web_ui/lib/src/engine/platform_views/content_manager.dart#L229-L238

## Issues

* Fixes flutter#141323

- [] I updated/added relevant documentation (doc comments with `///`).

Author: cedvdb

packages/pointer_interceptor/pointer_interceptor_web/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.10.1+2
+
+* Fixes "width and height missing" warning on web.
+
 ## 0.10.1+1
 
 * Updates minimum required plugin_platform_interface version to 2.1.7.

packages/pointer_interceptor/pointer_interceptor_web/lib/pointer_interceptor_web.dart

@@ -18,7 +18,10 @@ class PointerInterceptorWeb extends PointerInterceptorPlatform {
 
   // Slightly modify the created `element` (for `debug` mode).
   void _onElementCreated(Object element) {
-    (element as web.HTMLElement).style.backgroundColor = 'rgba(255, 0, 0, .5)';
+    (element as web.HTMLElement)
+      ..style.width = '100%'
+      ..style.height = '100%'
+      ..style.backgroundColor = 'rgba(255, 0, 0, .5)';
   }
 
   @override

packages/pointer_interceptor/pointer_interceptor_web/pubspec.yaml

@@ -2,7 +2,7 @@ name: pointer_interceptor_web
 description: Web implementation of the pointer_interceptor plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/pointer_interceptor/pointer_interceptor_web
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apointer_interceptor
-version: 0.10.1+1
+version: 0.10.1+2
 
 environment:
   sdk: ^3.2.0