Resolve T406989 "Proof of concept for adding new statements"

Proof of concept for adding new statements

Summary:

This PR demonstrates a proof of concept for adding new statements in Paulina. It includes a button called "Add information" below the biography table on the author page. When the user clicks on the button, the interface shows a dropdown including all the missing fields, after which the user can then select a field, and when they do that, a text box appears.

Files Modified:

File Path	Purpose
/templates/author.html	Updated author.html to include the new "Add Information" feature and a script for detection of missing fields and other dynamic interactions

Before:

Now:

When missing fields are spotted, the "Add information button is shown.

If there are no missing fields, I display: "All available fields are already complete"