Put X25519 and X448 back as approved algorithms

Put X25519 and X448 back as approved algorithms

CMVP's answer when questioned about this being:

    X448 and X25519 uses Curve448 and Curve25519, respectfully, within an
    ECDH scheme.  Therefore, it is possible for a key agreement scheme
    that uses Curve448 and Curve25519 to be used in the approved mode
    and be viewed as an allowed algorithm if requirements of Scenario
    X2 of IG D.8 and IG A.2 are met (or Scenario 3 of D.F and IG C.A for
    FIPS 140-3).  The use of EdDSA in the approved mode is not permitted
    until FIPS 186-5 is published and part of CMVP guidance.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20079)

(cherry picked from commit 8948b5749410084ed1dfabf17a90df65efcf0f82)