Uninstalling a XAR extension should not propose to delete pages that is also owned by another installed extension

If two XAR extensions install the same page, uninstalling one of them should not propose to delete the page, and in particular should not do so without information, or even worse checking the box.

To reproduce: use two different extension ID for the holding the same XAR in a wiki repos, and install both, then uninstall one of them.
Result: All the page are listed for deletion and checked.
Expectation: None of the page should be listed, or a mention of the other extension should be shown for them, or at least these should not be checked.