Add some `@since` annotations to `media-views.js`.

Props DrewAPicture.
See #28459.

Built from https://develop.svn.wordpress.org/trunk@29739


git-svn-id: http://core.svn.wordpress.org/trunk@29513 1a063a9b-81f0-0310-95a4-ce76da25c4cd
kses: Add colgroup.

props collinsinternet.
fixes #29433.

Built from https://develop.svn.wordpress.org/trunk@29740


git-svn-id: http://core.svn.wordpress.org/trunk@29514 1a063a9b-81f0-0310-95a4-ce76da25c4cd