apps: cover the dhparam -dsaparam file input in the test recipe

Reading DSA parameters from a file with -dsaparam and converting them
to X9.42 DH parameters was not covered, nor were the error paths when
the input file key type does not match the -dsaparam expectation.

Assisted-by: Claude:claude-fable-5
Reviewed-by: Daniel Kubec <kubec@openssl.foundation>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Merge-date: Mon Sep  7 14:14:08 2026
Merged-from: https://github.com/openssl/openssl/pull/32588