RSA: Be less strict on PSS parameters when exporting to provider

RSA: Be less strict on PSS parameters when exporting to provider

We have a key in test/recipes/30-test_evp_data/evppkey.txt with bad
PSS parameters (RSA-PSS-BAD), which is supposed to trigger signature
computation faults.  However, if this key needs to be exported to the
RSA provider implementation, the result would be an earlier error,
giving the computation that's supposed to be checked n chance to even
be reached.

Either way, the legacy to provider export is no place to validate the
values of the key.

We also ensure that the provider implementation can handle and detect
signed (negative) saltlen values.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/12583)