Plugins: Add focus style to plugin icon link in plugin cards.

This change adds a blue focus outline to the icon on plugin cards, for consistency with the text part of the link.

Props hitendra-chopda, SergeyBiryukov, afercia, themattroyal, imokol, sabernhardt, audrasjb.
Fixes #45209.


git-svn-id: https://develop.svn.wordpress.org/trunk@52790 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/common.css

@@ -270,6 +270,7 @@ a:active {
 
 a:focus,
 a:focus .media-icon img,
+a:focus .plugin-icon,
 .wp-person a:focus .gravatar {
 	color: #043959;
 	box-shadow: