Add Page -> Parent Page field not updating when page is added from a parent

When adding a page from another page, the Parent Page input from the Add Page modal does not update it's value if change. The change are reflected when creating the page, but there is no way for the user to know that unless he goes ahead and click Continue.


Here is a [video](https://drive.google.com/file/d/1oGKKQTuqpEf_pO3Cypf1Ma0gCj_quV2e/view?usp=sharing)

Start by reproducing the Add Page flow from a parent page and inspect the Add Page modal, especially the Parent Page input after changing its value. Confirm that the displayed value updates before Continue while the created page still receives the change; done means the modal visibly reflects the selected parent.

Written by the indexing model from the issue text.