Delete main category of product, product should be reassigned another main category

[arouiadib]

(Special thanks to @marionf, @matks, @Julievrz who already contributed to this VERY important matter.
The issue hugely affects how products are browsed by categories in FO).

What happens to the default category of a product P associated to category C when C is deleted and C is default category of P?

When merchant deletes category and chooses one of the two first options in modal (doesn't choose to delete associated products) THEN associate P to the parent category and set parent category as default.

some cases:

Behavior tests here: PrestaShop/PrestaShop#24668