Bugfix: Tiptap Link Picker, fixes anchor with an empty URL (#2522)

Tiptap Link Picker, fixes anchor with an empty URL

it was previous appending the anchor to a  stringified `null`.

Author: leekelleher

src/packages/tiptap/extensions/toolbar/link.extension.ts

@@ -75,7 +75,9 @@ export default class UmbTiptapToolbarLinkExtensionApi extends UmbTiptapToolbarEl
 
 		const anchor = this.#getAnchorFromQueryString(queryString);
 
-		if (anchor) url += anchor;
+		if (anchor) {
+			url = (url ?? '') + anchor;
+		}
 
 		if (!url) return null;