I'm not *super* sure why this works, but it appears to, and my educated
guess as to why is that it counteracts the effects of a change in the SV
of the juice stream by artificially increasing or decreasing the
velocity when running the appropriate path conversions and expected
distance calculations. The actual SV change takes effect on the next
default application, which is triggered by the `Update()` call at the
end of the method.
This is important because the editable path conversions heavily depend
on the value of `JuiceStream.Velocity` being correct. The value is only
guaranteed to be correct after an `ApplyDefaults()` call, which is
triggered by updating the object via `EditorBeatmap`.
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.
