Language Upgrader: Don't print a footer when translations are updated async.

fixes #28947.
Built from https://develop.svn.wordpress.org/trunk@29358


git-svn-id: http://core.svn.wordpress.org/trunk@29134 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Plugin install: Improve styling of the no results message.

see #28753.
Built from https://develop.svn.wordpress.org/trunk@29359


git-svn-id: http://core.svn.wordpress.org/trunk@29135 1a063a9b-81f0-0310-95a4-ce76da25c4cd