gh-37007: normalize projective points over (quotients of) Euclidean domains
Currently, projective points *over fields* are normalized to always have
$1$ as their last non-zero coordinate, but projective points over non-
fields are not normalized at all.
In this patch, we add similar normalization functionality for base rings
which are (1) Euclidean domains, or (2) quotients of Euclidean domains.
The most important examples are probably $\mathbb Z$ and $\mathbb Z/n$
for composite $n$.
URL: https://github.com/sagemath/sage/pull/37007
Reported by: Lorenz Panny
Reviewer(s): Giacomo Pope