B-Spline, Catmull-Rom, Hermite, NURBS Interpolation

[gregsn]

There are generic BSpline nodes in gamma 2022.5.

Those currently only support the Clamped mode, which luckily is exactly what we need for interpolation. In this mode, it is guaranteed that we get V = CP1 for t=0 and V = CPn for t=1.

It would be doable to add that interpolation mode today. It's just the question if we need it already. I just wanted to mention the possibility.

I would imagine a BSplineInterpolationModel (Restricted) with Spread<Object> to specify CP2 .. CPn-1. side discussion: A and B are the missing parts that get fed on Interpolate?? (see discussion: #247) It would maybe be cleaner if we just feed CP1 .. CPn whenever we want.
t1 .. tn would be linearly spreaded between 0..1. The UI would also display them linearly spreaded over time. This way we would have an easy way to do playful interpolation over time. The restriction to only play with the values, not with the times could potentially even contribute to the playfulness (one thing less to think about as a user...). To be explored.