Accessibility: Make links in the Customizer underlined by default.

Links within lines or blocks of text should always be underlined since they can't
rely on color alone to be distinguished from the surrounding text. Exceptions
can be handled on a case-by-case basis.

Props Presskopp for the initial patch.
Fixes #37527.


git-svn-id: https://develop.svn.wordpress.org/trunk@38503 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/customize-controls.css

@@ -3,7 +3,8 @@ body {
 	-webkit-text-size-adjust: 100%;
 }
 
-#customize-controls a {
+.customize-controls-close,
+.widget-control-actions a {
 	text-decoration: none;
 }