This commit re-implements the resample curve node to use the new curves
type instead of CurveEval. The largest changes come from the need to
keep track of offsets into the point array, and the fact that the
attributes for all curves are stored in a flat array.
Another difference is that a bit more of the logic is handled by
building on the field network inputs. The idea is to let the field
evaluator handle potential optimizations while making the rest of the
code simpler.
This also adds support for Catmull Rom curve inputs.