Cleanup: convert function nodes socket list to use new API

The new API was introduced in rB1e69a25043120cc8dddc3f58622eb50e1443def1.

Differential Revision: https://developer.blender.org/D12380

Geometry Nodes: Enhance the cube mesh primitive as a cuboid

This mesh primitive enhances the Cube mesh primitive and allows the
creation of a cuboid with a configurable size and number of vertices
in all 3 directions. The Cube primitive is now similar to the Grid
primitive except that it works in 3 dimensions.

Previously it was possible to create a cube and scale it arbitrarily
along each axis. You could also subdivide the mesh, but the number of
subdivisions was equal along all axes. This meant that making the basic
frame for something like modular buildings wasn't trivial.

Inspired by tutorials and files for modular building creation.

The cuboid is created as a `Mesh` so that large meshes with millions of
faces are created quickly. Though edge calculation could be faster if
implemented here, edges are calculated using `BKE_mesh_calc_edges`
to reduce complexity, and in hopes that they may be calculated lazily
for `Mesh` in the future like vertex normals.

See the differential revision for more information.

Differential Revision: https://developer.blender.org/D11810