Fix intermittent beatmap thumbnail test
Split out download logic from main manager classes
Split out legacy model export logic into `LegacyModelExporter` classes
Remove pointless interface class for `IBeatmapModelManager`
Move stable import handling out of `IModelManager<T>` into its own class
Confused why I added this in the first place..
IBeatmapModelManager
Was originally going to be used but serves no purpose any more.
GameHost
ScoreManager
BeatmapManager
Fix occasional test failure due to default value oversight in `TestSceneBeatmapCarousel`
LegacyModelExporter
IHasNamedFiles
Split out `SkinModelManager` from `SkinManager`
LegacyModelImporter
TestSceneBeatmapCarousel
Reduce interface exposure of `ScoreManager`
Stable
Legacy
SkinModelManager
SkinManager
Add automatic clean-up call for `RealmFileStore`
RealmFileStore
Cleanup
virtual
Refresh
FileStore.QueryFiles
Add preview track playback function to beatmap card
Fix multiplayer starting with own latest picked playlist item rather than the current playlist item
Initialise `IHasFiles<TFile>.Files` lists at construction time
Add online status to `RealmBeatmapSet`
Close a failed update notification immediately
Rename `BeatmapSetOnlineStatus` to `BeatmapOnlineStatus`
Combine all test data `BeatmapSetInfo` creation into a single method
Fixes visual issue pointed out at https://github.com/ppy/osu/discussions/15653#discussioncomment-1679263.