(from #31992)

#31942 added _sympy_ methods that provide conversion of Sage matrices and vectors to Sympy, as well as the conversion from Sympy to Sage using monkey-patched _sage_ methods.

Based on this, we can now implement various matrix methods using Sympy.

In this ticket, we add SVD (singular value decomposition) https://docs.sympy.org/latest/modules/matrices/matrices.html

This provides exact and symbolic SVD. Sage currently only has one implementation, for RDF, using scipy.linalg.

CC: @honglizhaobob

Component: linear algebra

Branch/Commit: u/mkoeppe/matrix__add_generic_svd_and_singular_values_methods_using_sympy @ 130033d

Issue created by migration from https://trac.sagemath.org/ticket/32171