Allow running individual FIPS self-tests

Allow running individual FIPS self-tests

This introduces a new function, `SELF_TEST_kats_single()`, to the FIPS
provider. This allows for deferring running the Known Answer Tests (KATs)
for a specific algorithm. This is useful to avoid running
computationally costly tests upfront and instead run them only if the
algorithm is actually going to be used.

To support this, a `deferred` flag has been added to the test data
structures. The main self-test function, `SELF_TEST_kats()`, is updated to
skip tests marked for deferred execution, preserving its existing startup
behavior for all other tests.

Signed-off-by: Simo Sorce <simo@redhat.com>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/28725)