Lexical: Added basic URL field header option list

May show bad option label names on chrome/safari.
This was an easy first pass without loads of extra custom UI since we're
using native datalists.

resources/js/services/util.js

@@ -84,6 +84,17 @@ export function uniqueId() {
     return (`${S4() + S4()}-${S4()}-${S4()}-${S4()}-${S4()}${S4()}${S4()}`);
 }
 
+/**
+ * Generate a random smaller unique ID.
+ *
+ * @returns {string}
+ */
+export function uniqueIdSmall() {
+    // eslint-disable-next-line no-bitwise
+    const S4 = () => (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
+    return S4();
+}
+
 /**
  * Create a promise that resolves after the given time.
  * @param {int} timeMs