Accessibility: Site Health: Improve the "Copy site info" button accessibility.

- avoids a focus loss when clicking the "Copy site info" button
- uses `setTimeout()` and `clearTimeout()` to properly handle the "Copied!" text
- minor JavaScript coding standards

Props audrasjb, Clorith, afercia.
See #48463, #50335.
Fixes #50322.


git-svn-id: https://develop.svn.wordpress.org/trunk@48233 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/site-health.css

@@ -203,22 +203,16 @@
 }
 
 .site-health-copy-buttons .copy-button-wrapper {
+	display: inline-flex;
+	align-items: center;
 	margin: 0.5rem 0 1rem;
 }
 
 .site-health-copy-buttons .success {
-	display: none;
 	color: #40860a;
-	line-height: 1.8;
 	margin-left: 0.5rem;
 }
 
-.site-health-copy-buttons .success.visible {
-	display: inline-block;
-	height: 30px;
-	line-height: 2.30769231;
-}
-
 .site-status-has-issues.hide {
 	display: none;
 }
@@ -456,6 +450,10 @@
 		padding-bottom: 0;
 		font-weight: 600;
 	}
+
+	.wp-core-ui .site-health-copy-buttons .copy-button {
+		margin-bottom: 0;
+	}
 }
 
 /* The breakpoint is usually at 960px, the additional space is to allow for the margin. */