Add screen reader text to announce that menu item accordion sections are expandable. Remove redundant title attribute.

props joedolson.
fixes #28866.
Built from https://develop.svn.wordpress.org/trunk@29239


git-svn-id: http://core.svn.wordpress.org/trunk@29023 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Customizer: Add screen reader text to announce that panels and sections are expandable.

props joedolson, ocean90.
fixes #27591.
Built from https://develop.svn.wordpress.org/trunk@29240


git-svn-id: http://core.svn.wordpress.org/trunk@29024 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add a class for get_comment_author_link() in Recent Comments widget.

props DrewAPicture, dannydehaan, 5um17.
fixes #27944.
Built from https://develop.svn.wordpress.org/trunk@29241


git-svn-id: http://core.svn.wordpress.org/trunk@29025 1a063a9b-81f0-0310-95a4-ce76da25c4cd