Move plotting and affine hull to Polyhedron_base6

[kliem]

Part of #32651.

We move plotting and affine hull methods to Polyhedron_base6.

CC: @mkoeppe

Component: geometry

Author: Jonathan Kliem

Branch: cf92e9f

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/33449

[kliem]

Author: Jonathan Kliem

[mkoeppe]

comment:2

The new file is not on the branch

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

cf92e9f

add new file

[sagetrac-git]

Changed commit from 5c726dc to cf92e9f

[kliem]

comment:4

Forgot that.

[mkoeppe]

Reviewer: Matthias Koeppe

[mkoeppe]

comment:6

The doctest failure is unrelated.

[kliem]

comment:7

Thank you.