make elliptic-curve isogenies compute Montgomery codomains

[yyyyx4]

Following up on #33707, we can support passing model="montgomery" to the various isogeny functions in Sage.

Diff without the dependencies: sagemath/sagetrac-mirror@2833869...ec0aaf3

Depends on #33619
Depends on #33707

CC: @defeo @JohnCremona @categorie

Component: elliptic curves

Author: Lorenz Panny

Branch/Commit: ec0aaf3

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/33708

[sagetrac-git]

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

628110e	Merge tag '9.6.rc1' into public/montgomerize_isogeny_codomains
0242e3c	remove unused import

[sagetrac-git]

Changed commit from 4c145ed to 0242e3c

[sagetrac-git]

Changed commit from 0242e3c to 295b299

[sagetrac-git]

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

240cf80	Merge branch 'develop' into t/33707/public/montgomerize_elliptic_curves-test
c093464	Some edits mostly improving readibility of code
ff391f9	One more edit
af5081a	Merge tag '9.6.rc3' into public/montgomerize_elliptic_curves
4e380e2	some more style tweaks
295b299	Merge branch 'public/montgomerize_elliptic_curves' into public/montgomerize_isogeny_codomains

[sagetrac-git]

Changed commit from 295b299 to ec0aaf3

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. Last 10 new commits:

206f62a	spaces after commas
68cfda6	small tweaks in docstring
cdab998	demonstrate vanishing on full 2-torsion in example
37346c8	remove some unnecessary polynomial-to-list conversions
454f3ed	E2 -> codomain in method names
f131ae3	code style tweaks
de6552e	hide internal helper function
2833869	some doc tweaks
6f0ffee	Merge branch 'public/clean_up_ell_curve_isogeny_file' into public/montgomerize_isogeny_codomains
ec0aaf3	doc tweak

[tscrim]

comment:7

LGTM.

[tscrim]

Reviewer: Travis Scrimshaw

[vbraun]

Changed branch from public/montgomerize_isogeny_codomains to ec0aaf3