Add a workaround for replacing core notice Site updated

I considered doing this using a filter 'i18n.gettext', but
with this approach, we would just replace the text. The notice also
contained an action with a link to the site's homepage, so I chose this mechanism instead.
Let's see if there will be more use-cases. We can eventually move it somewhere into the store
and proxy all messages via our store.
[MAILPOET-6336]

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

@@ -1,4 +1,6 @@
+import { useMemo } from '@wordpress/element';
 import { SnackbarList } from '@wordpress/components';
+import { __ } from '@wordpress/i18n';
 import { useSelect, useDispatch } from '@wordpress/data';
 import { store as noticesStore } from '@wordpress/notices';
 
@@ -12,11 +14,33 @@ export function EditorSnackbars( { context = 'email-editor' } ) {
 		[ context ]
 	);
 
+	// Some global notices are not suitable for the email editor context
+	// This map allows us to change the content of the notice
+	const globalNoticeChangeMap = useMemo( () => {
+		return {
+			'site-editor-save-success': {
+				content: __( 'Template updated.', 'mailpoet' ),
+				removeActions: true,
+			},
+		};
+	}, [] );
+
 	const { removeNotice } = useDispatch( noticesStore );
 
-	const snackbarNotices = notices.filter(
+	const snackbarNotices = notices
-		( { type } ) => type === 'snackbar'
+		.filter( ( { type } ) => type === 'snackbar' )
-	);
+		.map( ( notice ) => {
+			if ( ! globalNoticeChangeMap[ notice.id ] ) {
+				return notice;
+			}
+			return {
+				...notice,
+				content: globalNoticeChangeMap[ notice.id ].content,
+				actions: globalNoticeChangeMap[ notice.id ].removeActions
+					? []
+					: notice.actions,
+			};
+		} );
 
 	return (
 		<SnackbarList