Handle an error on UI when importing a page with the same name siblings

Steps to reproduce

1. Export a page 
2. Import that page at the same level (at root)

.. Logs, screenshots, gifs...

Expected results

Should not throw an error on browser.

Maybe show a warning message when importing the same name siblings.

Actual results

Same name siblings are not allowed on Magnolia. It throws an error which is not clear for user on browser.

Workaround

Development notes