Add support for Spotify countdown pages

[wileyfoxyx]

Since late July 2024, artists that have ≥50K listeners on Spotify, can create "Countdown Pages" for their upcoming releases, unlike iTunes/Apple Music that allows it only if distributor does.

Example for page: https://open.spotify.com/prerelease/3hE7bXlfNHQYcYjH90VwkN?si=e857a1c0ff2b4e92

[kellnerd]

Unfortunately the Spotify API doesn't support these, so I am marking this as blocked.
The pre-release IDs aren't stable either, they redirect once the release has happened, see MBS-13362.