tests: Introduce optional RNG seed for boost suite
tests: Introduce optional RNG seed for boost suite

Today, if you want to reproduce a rare condition using the same RNG seed
reported, you cannot use test.py which provides useful infrastructure
and will have to run the tests manually instead.
So let's extend test.py to allow optional forwarding of RNG seed to
boost tests only, as other suites don't support the seed option.

Signed-off-by: Raphael S. Carvalho <1e2942cea40e3b4d2162dfcd9e53e41c05a84d22@scylladb.com>
Message-Id: <20220615223657.142110-1-1e2942cea40e3b4d2162dfcd9e53e41c05a84d22@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla