Migrate url module to TS

src/annotator/util/url.js → src/annotator/util/url.ts

@@ -3,11 +3,13 @@
  *
  * This makes it absolute and strips the fragment identifier.
  *
- * @param {string} uri - Relative or absolute URL
- * @param {string} [base] - Base URL to resolve relative to. Defaults to
- *   the document's base URL.
+ * @param uri - Relative or absolute URL
+ * @param base - Base URL to resolve relative to. Defaults to the document's base URL.
  */
-export function normalizeURI(uri, base = document.baseURI) {
+export function normalizeURI(
+  uri: string,
+  base: string = document.baseURI
+): string {
   const absUrl = new URL(uri, base).href;
 
   // Remove the fragment identifier.