In some cases `SliderPath.GetPathToProgress` used to compute the whole
path when it can be not needed since it can be already stored inside
`calculatedPath` list.
Also some of these use cases will no longer require additional array
wheen only readonly access is all we need.
This is quite a breaking change, but I think it is beneficial due to the large amount of usage of this class.
I originally intended just to remove the allocations of the two delegates handling the `Changed` flow internally, but as nothing was really using the bindables for anything more than a general "point has changed" case, this felt like a better direction.
A `JuiceStream` holds a legacy `SliderPath` as the representation of the path.
However, the `SliderPath` representation is difficult to work with because `SliderPath` works in 2D position, while osu!catch works in `(time, x)` coordinates.
This `JuiceStreamPath` represents the path in a more convenient way, a polyline connecting list of `(distance, x)` vertices.