Trac #32776: split convex set methods of polyhedra into base1.py

Part of #32651.

Outsource convex set methods of polyhedra, but not those that construct
new polyhedra.

URL: https://trac.sagemath.org/32776
Reported by: gh-kliem
Ticket author(s): Jonathan Kliem
Reviewer(s): Matthias Koeppe

Author: Release Manager

src/sage/geometry/abc.pyx

@@ -72,7 +72,7 @@ class Polyhedron:
     By design, there is a unique direct subclass::
 
         sage: sage.geometry.abc.Polyhedron.__subclasses__()                   # optional - sage.geometry.polyhedron
-        [<class 'sage.geometry.polyhedron.base.Polyhedron_base'>]
+        [<class 'sage.geometry.polyhedron.base0.Polyhedron_base0'>]
 
         sage: len(sage.geometry.abc.Polyhedron.__subclasses__()) <= 1
         True