Fix ambiguous output of Signature Algorithms

Fix ambiguous output of Signature Algorithms

Signature Algorithms are printed in a SIG+HASH format.
In some cases this is ambiguous like brainpool and RSA-PSS.
And the name of ed25519 and ed448 must be spelled in lower case,
so that the output can be used as a -sigalgs parameter value.

Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/25797)