During creation of the EVP_PKEY_CTX we were trying to discover what legacy
alg it corresponds to every time which was slow. Instead we move this into
the construction of the EVP_KEYMGMT.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23265)