In the media modal, ensure modal events are always fired on its frame. This...

In the media modal, ensure modal events are always fired on its frame. This ensures restoreThickbox() and thus tbRemove() are called properly when clicking the close button of the modal.

Props koopersmith
fixes #22632


git-svn-id: https://core.svn.wordpress.org/trunk@22938 1a063a9b-81f0-0310-95a4-ce76da25c4cd