feat(AlgebraicGeometry/Restrict): a few more restriction lemmas

[justus-springer]

These will be used later to define composition of rational maps in #39445.

---

[github-actions]

PR summary a884fb60c6

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ Scheme.Hom.isoImage_hom_homOfLE
+ Scheme.Hom.isoImage_inv_homOfLE
+ Scheme.Opens.ι_isoImage_inv_ι
+ morphismRestrict_eq_isoImage_hom_homOfLE
+ morphismRestrict_homOfLE
+ morphismRestrict_homOfLE_ι_isoImage_hom
+ morphismRestrict_morphismRestrict_ι_isoImage_hom
+ morphismRestrict_ι_image_ι_isoImage_inv
+ ι_isoImage_inv_morphismRestrict_homOfLE

You can run this locally as follows

## from your `mathlib4` directory:
git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci

## summary with just the declaration names:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh in the mathlib-ci repository contains some details about this script.

---

No changes to strong technical debt.

No changes to weak technical debt.