Improve compatibility of point and curve checks

Improve compatibility of point and curve checks

We check that the curve name associated with the point is the same as that
for the curve.

Fixes #6302

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6323)

(cherry picked from commit b14e60155009f4f1d168e220fa01cd2b75557b72)