Extended text masking function to include relevant HTMLElement (#1310)

* Extends maskTextFn to pass the HTMLElement to the deciding function

---------

Authored-by: benjackwhite <benjackwhite@users.noreply.github.com>
Co-authored-by: Justin Halsall <Juice10@users.noreply.github.com>
Co-authored-by: Eoghan Murray <eoghan@getthere.ie>

packages/rrweb-snapshot/src/snapshot.ts

@@ -575,7 +575,7 @@ function serializeTextNode(
     needMaskingText(n, maskTextClass, maskTextSelector)
   ) {
     textContent = maskTextFn
-      ? maskTextFn(textContent)
+      ? maskTextFn(textContent, n.parentElement)
       : textContent.replace(/[\S]/g, '*');
   }