Accessibility: Improve the Comments and Privacy count text.

- standardizes the Comment count string to `%s Comment in moderation', '%s Comments in moderation` so it can be bulk-updated
- adds the string as visually hidden text in the admin menu 
- introduces an `updateInModerationText` JS simple function, responsible to correctly update all the related text using the data from the AJAX response
- adds a visually hidden text "1 Privacy Policy update" to the Privacy menu items count
- adds/improves translators comments

Changes that apply to all the count bubbles (Updates, plugins, etc.)
- makes the bubbles and their text slightly bigger
- improves the active menu item bubble contrast by changing the background color to red (option 2 in the screenshot attached in a previous comment)

Props adamsoucie, afercia.
Fixes #33030.

Built from https://develop.svn.wordpress.org/trunk@44924


git-svn-id: http://core.svn.wordpress.org/trunk@44755 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/admin-bar.php

@@ -885,11 +885,15 @@ function wp_admin_bar_comments_menu( $wp_admin_bar ) {
 
 	$awaiting_mod  = wp_count_comments();
 	$awaiting_mod  = $awaiting_mod->moderated;
-	$awaiting_text = sprintf( _n( '%s comment awaiting moderation', '%s comments awaiting moderation', $awaiting_mod ), number_format_i18n( $awaiting_mod ) );
+	$awaiting_text = sprintf(
+		/* translators: %s: number of comments in moderation */
+		_n( '%s Comment in moderation', '%s Comments in moderation', $awaiting_mod ),
+		number_format_i18n( $awaiting_mod )
+	);
 
 	$icon   = '<span class="ab-icon"></span>';
 	$title  = '<span class="ab-label awaiting-mod pending-count count-' . $awaiting_mod . '" aria-hidden="true">' . number_format_i18n( $awaiting_mod ) . '</span>';
-	$title .= '<span class="screen-reader-text">' . $awaiting_text . '</span>';
+	$title .= '<span class="screen-reader-text comments-in-moderation-text">' . $awaiting_text . '</span>';
 
 	$wp_admin_bar->add_menu(
 		array(