This adds support for `Bézier` and `Catmull Rom` curve types to the
interpolation tool.
When interpolating between to curves of different types, a priority
system is used.
The priorities from highest for lowest are in the order
`NURB`, `Bézier`, `Catmull Rom` and `Polyline`.
The reasoning for this order is that:
- `NURBs` can be degree order 5 or greater, were as `Bézier` is only
order 4.
- `Bézier` can match the form of both `Catmull Rom` and `Polyline`, so
should be higher priority.
- `Catmull Rom` is continuous.
- `Polyline` is the simplest and is not smooth, so it should be last.
Note: This does add some simple `NURBs` interpolation, but proper
handling is more complicated and will be save for a future PR.
Resolves: #141178, #143377, #133948 and #136087
Pull Request: https://projects.blender.org/blender/blender/pulls/145683
1dd536e24f