Global playlist is no longer shuffled (since realm switch)

[peppy]

Since switching to realm, beatmaps are arbitrarily ordered by the order they were added to the database. This means that there is a guaranteed order of playback at the main menu, which feels pretty wrong.

Currently:

• MusicController has a stable next/prev operation that offers no randomisation.
• The now playing playlist overlay shows the matching list of beatmaps in the order they will be played.
• Song select has an actual random implementation (with associated user setting).

It seems like users will want to use the playlist overlay to potentially limit and order playback. Therefore, I'd propose that MusicController needs to maintain a list of playback order. In addition, one of the two paths forward:

• The game should randomise the order stored in MusicController if the user doesn't have a custom playlist selected, each startup.
• The game should use a stable method to decide the order, but we would add a "shuffle" button to the now playing overlay which advances in a non-sequential order (and this would be enabled by default).

I'm thinking the second path sounds best.

Discussed in #18139

^{Originally posted by Jacie1krece May 8, 2022}
Hi,
when checking osu!lazer for a behavior that existed before (something simlar to the first-born syndrome, but with songs automatically playing (leaving osu! on the main menu for it to play randomly)), it somehow was bugged/changed. First, all of the "date added" sorting was completly random for seemingly no reason (For future reference, the bottom-most songs were No Title, Happppy Song, iiillluuuvvvUUU, Happppy Song and Raven Haven - it has been that way in osu!lazer since I first imported songs from osu!stable), and the old "date added" sorting is used as a reference in the automatic playing - newest additions being suspiciously together with SOOOO's song confirming that behavior. Could someone tell me please, what happened and is it a bug?