To go alongside the new downloader/installer, we want to do a pass on the complete UX when it comes to installing collections, primarily with the notifications.

So @captainsandypants can assess what we have, without just installing a collection, we need to get a list of all notifications/user feedback that are raised. Notifications, dialogs, modals etc. Some of the error ones are harder to raise so we should be able to get the info out of the code. We will need when the notification is displayed, what type of notification (severity? auto dismiss?), what buttons it has, what happens when they are clicked, what text is shown etc.

This is linked to #18217