Use is_manifold_like

[lukem12345]

CombinatorialSpaces.jl offers the is_manifold_like function which tests certain combinatorial-properties of a manifold-like simplicial set. (Note that some not-tested-for-properties, such as whether a manifold is a single connected component, do not obstruct us simulating physics on them.)

We should call is_manifold_like as part of our gensim pipeline. This will catch bugs early and provide helpful error messages.

Note that is_manifold_like uses the older d reference implementation, and so using dec_differential there should be upstreamed.