[pointer_interceptor] Move pointer_interceptor to sub folder (flutter#5291)

Prep PR for flutter/packages#5233

Author: LouiseHsu

packages/pointer_interceptor/.gitignore renamed to packages/pointer_interceptor/pointer_interceptor/.gitignore

@@ -1,3 +1,7 @@
+## 0.9.3+7
+
+* Updates metadata to point to new source folder
+
 ## 0.9.3+6
 
 * Migrates to `dart:ui_web` APIs.

packages/pointer_interceptor/.metadata renamed to packages/pointer_interceptor/pointer_interceptor/.metadata

@@ -1,8 +1,8 @@
 name: pointer_interceptor
 description: A widget to prevent clicks from being swallowed by underlying HtmlElementViews on the web.
-repository: https://github.com/flutter/packages/tree/main/packages/pointer_interceptor
+repository: https://github.com/flutter/packages/tree/main/packages/pointer_interceptor/pointer_interceptor
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+pointer_interceptor%22
-version: 0.9.3+6
+version: 0.9.3+7
 
 environment:
   sdk: ">=3.1.0 <4.0.0"