Three bindables are left which don't have this overriden due to them
already not having a value-only constructor and not supporting
`GetBoundCopy()` properly:
- `BeatmapDifficultyCache.BindableStarDifficulty`.
- `TotalScoreBindable`
- `TotalScoreStringBindable`
I could add support for them by passing the required data to them, as
they seem to be able to have that shared, but I'm hesitant to support
something which was already broken and never used, not sure.
This was causing any `ValueChanged` event bind (such as the one in
`SettingsItem` to invoke `SettingsChanged`) to be overwritten when
`Current` is set afterwards.
- make `UserActivity.InGame` and derive that to `InSoloGame` and `InMultiplayerGame`
- rename `SoloGame` to `InSoloGame`
- rename `MultiplayerGame` to `InMultiplayerGame`
With the previous commit, the transform application is skipped when the state is already changed. But it turns out the previous commit breaks slider animation in the standard editor. This is probably due to the transforms are applied before nested hit objects are added.