Simplify setting and getting "edges" of edges, ridges, incidences in `CombinatorialPolyhedron`

[kliem]

In CombinatorialPolyhedron the same very basic DiGraph data structure is used for three different purposes:

• edges,
• ridges,
• incidences.

We collect setting and getting of edges in two methods to reduce code duplication.

Background:

The idea is to collect edges of a graph almost without overhead.
Currently up to 16348 edges are saved in a list of length 2*16348*sizeof(size_t). To allow more edges (while avoiding large chunks of continuous memory), we keep the edges in a lists of lists.

CC: @tscrim

Component: geometry

Keywords: code duplication, combinatorial polyhedron

Author: Jonathan Kliem

Branch/Commit: bde0945

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/30443

[tscrim]

comment:3

LGTM.

[tscrim]

Reviewer: Travis Scrimshaw

[kliem]

comment:4

Thanks.

[vbraun]

Changed branch from u/gh-kliem/simplify_edges_ridges to bde0945