Media library: Unify headers between view modes.

Includes back compat for `views_upload` links. These look a little awkward, but do not appear to be commonly used. Also prevents the view mode links from being dropped on smaller screens so a user doesn't get "stuck" in the list view.

This is different from other list tables, but aligns well with other uploaded content management screens (themes, plugins).

props pento, helen.
fixes #28946.

Built from https://develop.svn.wordpress.org/trunk@29625


git-svn-id: http://core.svn.wordpress.org/trunk@29399 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix a CSS typo from [29625]. see #28946.

Built from https://develop.svn.wordpress.org/trunk@29626


git-svn-id: http://core.svn.wordpress.org/trunk@29400 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Give pagination controls some breathing room on smaller screens.

props stephdau.
fixes #29369.

Built from https://develop.svn.wordpress.org/trunk@29627


git-svn-id: http://core.svn.wordpress.org/trunk@29401 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Editor scrolling: reduce the amount of height jumping on load.

props avryl.
fixes #29307.

Built from https://develop.svn.wordpress.org/trunk@29628


git-svn-id: http://core.svn.wordpress.org/trunk@29402 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Media: only apply `wp-filter` class to the grid view toolbar.

props gcorne.
fixes #29381.

Built from https://develop.svn.wordpress.org/trunk@29629


git-svn-id: http://core.svn.wordpress.org/trunk@29403 1a063a9b-81f0-0310-95a4-ce76da25c4cd