Allow some imports of RLF to fail #32777
Description
The RealLazyField implementation is tied closely to real_mpfr.
We modify some imports for the purpose of modularization, in particular sagemath-polyhedra (#32432)
In particular for ... is RLF tests:
$ git grep 'is RLF'
src/sage/rings/complex_double.pyx: if S is ZZ or S is QQ or S is RDF or S is RLF:
src/sage/rings/number_field/number_field_base.pyx: if codomain is AA or codomain is RLF:
src/sage/rings/real_double.pyx: if S is ZZ or S is QQ or S is RLF:
src/sage/schemes/plane_conics/con_number_field.py: if not (isinstance(p, Map) and p.category_for().is_subcategory(Rings())) or p.codomain() is AA or p.codomain() is RLF:
Depends on #32742
Depends on #32750
Depends on #32733
CC: @kliem @tscrim @sagetrac-tmonteil
Component: refactoring
Author: Matthias Koeppe
Branch/Commit: b49bbdf
Reviewer: Travis Scrimshaw
Issue created by migration from https://trac.sagemath.org/ticket/32777