Improve error message when creating templates with the same title from an archived page

Summary

Upon creating pages using certain templates like the product requirements one, a parent/indexing page will be created to display all pages using this template, called "Product requirements".

Due to CONFCLOUD-74688, upon trying to create a page using the template in question, generic error messages are displayed:

We're having trouble connectin right now

Give us a few seconds to reconnec, and you can resume your work

On the top-right:

Something's gone wrong.

Try again later.

Suggestion

As the error message suggests the user tries again and it will not resolve the issue, similar to what happens if a page with the same title from an archived page is attempted to be created, this is a suggestion to provide a clear message, stating that there is a page with the same title from the parent/indexing page that will be created.