**What**
- Re-works how toasts work in Medusa UI. API is now built on top of `sonner` instead of `@radix-ui/react-toast`. This is a breaking change, and we will need to update the documentation once this has been merged and released (cc: @shahednasser).
- Adds an example of usage in the products list table in the new admin dashboard. As part of the coming weeks cleanup we will add toasts everywhere that they are currently missing.
CLOSES CORE-1977
