The task of computing the matrix by which an isogeny acts on a particular n‑torsion subgroup often comes up in algorithms for supersingular elliptic curves. (In particular, it appears as a subroutine of computing the kernel of an endomorphism-ring ideal.)

This patch adds a simple method to compute such a matrix, based on AdditiveAbelianGroupWrapper.discrete_log().

(The dependency is only necessary for the reference in the "see also" block.)

Depends on #34718

Component: elliptic curves

Author: Lorenz Panny

Branch/Commit: public/matrix_of_isogeny @ 0bc249d

Issue created by migration from https://trac.sagemath.org/ticket/34879