XFA - Remove namespace from nodes under xfa:data node

- in real life some xfa contains xml like <xfa:data><xfa:Foo><xfa:Bar>...</xfa:data>
    since there are no Foo or Bar in the xfa namespace the JS representation are empty
    and that leads to errors.
  - so the idea is to make all nodes under xfa:data namespace agnostic which means
    that ns are removed from nodes in the parser but only xfa:data descendants.

src/core/xfa/xfa_object.js

@@ -60,6 +60,7 @@ const $isCDATAXml = Symbol();
 const $isBindable = Symbol();
 const $isDataValue = Symbol();
 const $isDescendent = Symbol();
+const $isNsAgnostic = Symbol();
 const $isSplittable = Symbol();
 const $isThereMoreWidth = Symbol();
 const $isTransparent = Symbol();
@@ -160,6 +161,10 @@ class XFAObject {
     );
   }
 
+  [$isNsAgnostic]() {
+    return false;
+  }
+
   [$acceptWhitespace]() {
     return false;
   }
@@ -1087,6 +1092,7 @@ export {
   $isCDATAXml,
   $isDataValue,
   $isDescendent,
+  $isNsAgnostic,
   $isSplittable,
   $isThereMoreWidth,
   $isTransparent,