Update dependencies for version 20.0.0-alpha2

package.json

@@ -44,6 +44,7 @@
     "@vaadin/vaadin-lumo-styles": "^1.6.1",
     "@vaadin/vaadin-material-styles": "^1.3.2",
     "@vaadin/vaadin-menu-bar": "^2.0.0",
+    "@vaadin/vaadin-messages": "^2.0.0-alpha1",
     "@vaadin/vaadin-notification": "^1.6.1",
     "@vaadin/vaadin-ordered-layout": "^1.4.0",
     "@vaadin/vaadin-overlay": "^3.5.1",