Change numbering of sub-entities?

Currently, sub-entities of the reference cell are numbered following the [UFC convention](https://fossies.org/linux/ufc/doc/manual/ufc-user-manual.pdf) on simplex cells:

> When the vertices have been numbered, the remaining mesh entities are numbered within each topological dimension based on a lexicographical ordering of the corresponding ordered tuples of non-incident vertices.

However non-simplex cells instead are ordered by **incident** vertices. This matches the convention used by [DefElement](https://doi.org/10.1007/s44207-026-00011-0):

>

This inconsistency is a little confusing. I propose that we update the numbering of sub-entities on simplex cells so that all cells match the DefElement conventions