Use text compare for PEM and text files

Use text compare for PEM and text files

- Fix ml_dsa_codecs test
- Fix ml_kem_codecs test
- Fix pkey test
- Fix dsaparam test
- Fix dhparam test
- Fix pkcs8 test

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/27082)