Update notice text when saving template or global styles

The code triggers the same notice for changes in a template or changes in global styles.
This commit makes the text of the notice more generic to work for both.
[MAILPOET-6335]

packages/js/email-editor/src/components/notices/snackbars.tsx

@@ -19,7 +19,7 @@ export function EditorSnackbars( { context = 'email-editor' } ) {
 	const globalNoticeChangeMap = useMemo( () => {
 		return {
 			'site-editor-save-success': {
-				content: __( 'Template updated.', 'mailpoet' ),
+				content: __( 'Email design updated.', 'mailpoet' ),
 				removeActions: true,
 			},
 		};