I18N: Set translations for all WordPress packages scripts.

Calls `wp_set_script_translations` for all packages scripts that have translations. Also correctly sets the domain on the translations.

Props omarreiss, pento, ocean90.
Merges [43878] to trunk.
Fixes #45161.
Built from https://develop.svn.wordpress.org/trunk@44239


git-svn-id: http://core.svn.wordpress.org/trunk@44069 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class.wp-scripts.php

@@ -546,7 +546,8 @@ class WP_Scripts extends WP_Dependencies {
 		}
 
 		$output = '(function( translations ){' .
-					  'wp.i18n.setLocaleData( translations.locale_data, "' . $domain . '" );' .
+					  'translations.locale_data.messages[""].domain = "' . $domain . '";' .
+					  'wp.i18n.setLocaleData( translations.locale_data.messages, "' . $domain . '" );' .
 				  '})(' . $json_translations . ');';
 
 		if ( $echo ) {