refs #15956 [fid] fix in lightbox_form_cache.js

* adds textareas to cached input elements

themes/finc/js/lightbox_form_cache.js

@@ -26,7 +26,8 @@ document.addEventListener('DOMContentLoaded', function () {
     const cacheKeyBase = Array.from(form.attributes).map(attr => attr.value);
     const cacheKey = cacheKeyPrefix + btoa(cacheKeyBase.join());
 
-    const inputs = Array.from(form.querySelectorAll('input:not([type=password])'));
+    const inputs = Array.from(form.querySelectorAll('input:not([type=password])'))
+        .concat(Array.from(form.querySelectorAll('textarea')));
     JSON.parse(cache.getItem(cacheKey) || '[]').forEach(function (value, index) {
       inputs[index].value = value;
     });