Test random generation as a whole. This is different from
test_suite_*_drbg and test_suite_entropy, which respectively test PRNG
modules and entropy collection.
Start with basic tests: good-case tests, and do it twice and compare
the results to validate that entropy collection doesn't repeat itself.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
