In the Edit Attachment frame, when in Edit Image mode, add a key event for Escape. There are conflicting `keydown` handlers that don't propagate the event to the modal properly.

Fixes #29121.

Built from https://develop.svn.wordpress.org/trunk@29481


git-svn-id: http://core.svn.wordpress.org/trunk@29259 1a063a9b-81f0-0310-95a4-ce76da25c4cd