Use static parameters for indexing in DSS

[charleskawczynski]

In similar light of #1894, we should use statically passed parameters in DSS. For example, in:

    if gidx ≤ nlevels * nfidx * nghostvertices
        sizev = (nlevels, nfidx, nghostvertices)
        (level, fidx, vertexid) = cart_ind(sizev, gidx).I

nlevels, nfidx, and nghostvertices should be passed through the type domain.

[charleskawczynski]

Closed by #1934