MDL-77174 core: Add getElement to core/normalise

lib/amd/src/normalise.js

@@ -65,3 +65,27 @@ export const getFirst = nodes => {
     const list = getList(nodes);
     return list[0];
 };
+
+/**
+ * Normalise a single node into an HTMLElement.
+ *
+ * @param {jQuery|Y.Ndoe|HTMLELement} node The node to normalise
+ * @returns {HTMLElement}
+ */
+export const getElement = (node) => {
+    if (node instanceof HTMLElement) {
+        return node;
+    }
+
+    if (node?._node) {
+        // This is likely a YUI Node.
+        // We can use (node instanceof Y.Node) but we would have to load YUI to do some.
+        return node._node;
+    }
+
+    if (node instanceof jQuery && node.length > 0) {
+        return node.get(0);
+    }
+
+    return null;
+};