Support the hash algorithms PSA_ALG_SHAKE128_256 (one of the officially permitted pre-hash functions for HashML-DSA) and PSA_ALG_SHAKE256_512 (the only permitted pre-hash function for Ed448ph).
Prerequisite: built-in SHAKE
Work in progress in Mbed-TLS/mbedtls-framework#267 + https://github.com/gilles-peskine-arm/TF-PSA-Crypto/tree/sha3-shake-builtin-2 . That branch also contains built-in SHAKE, it was an earlier proposal for #648 which was then scoped down.