In preparation to remove `DistancedHitObjectComposer`, split off
`IPositionSnapProvider` from `IDistanceSnapProvider`.
`DistancedHitObjectComposer` was not touching `IPositionSnapProvider`'s
only interface member at all, it was just forwarding it for subclasses
to override to their own leisure.
This multiplier has to exist.
I'm not guaranteeing that the rest is correct here. Should we be doing
proper cross-testing on this? Maybe, but it's going to be hard to get
right. We could likely check as far as "game pixels", but there's still
a chance that the osu-framework could be doing something weird in the
rest of the hierarchy where playfield scale is involved.
Closes https://github.com/ppy/osu/issues/25162. Tested to fix the linked
replay.