Race conditions can cause `.uploader-window` to be visible with opacity of `0`. It will cause the user to have to refresh the page or inspect the element to hide it. Add a delay in `wp.media.view.UploaderWindow.hide()` to ensure that the uploader window is indeed hidden.

Props kovshenin.
Fixes #27341.

Built from https://develop.svn.wordpress.org/trunk@28838


git-svn-id: http://core.svn.wordpress.org/trunk@28642 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Dynamically prepend screen reader text to the attachment filters dropdown and the search box in the media modal.

Props SergeyBiryukov.
Fixes #25102.

Built from https://develop.svn.wordpress.org/trunk@28839


git-svn-id: http://core.svn.wordpress.org/trunk@28643 1a063a9b-81f0-0310-95a4-ce76da25c4cd