No "clipping" occur anymore for vertex positions. Instead, clipping may occur when the path is converted to a slider. Add tests for automatic slider velocity change.
JuiceStreamPath
And remove the "slope limit" feature. TODO: for a juice stream with a large slope, the slider velocity of the hit object should be changed.
var
BaseDifficulty
Beatmap<T>
.Value
Changing from `Bindable` to `Nullable` comes with its issues...