This shuffles all of SQL's QA tests into the `qa/sql` directory, moving
some shared resources into the new `qa:sql` project. It also rigs up
testing of the rest SQL interface in all the sql qa configurations:
without security, with security, and against multiple nodes.
I've had to make some modifications to how we handle the audit log
because it has gotten pretty slow. If these modifications turn out to
not be fast enough then I'll change the test to querying the log files
and drop the audit log index entirely but the index seems to be holding
out for now.
Original commit: elastic/x-pack-elasticsearch@ff3b5a74c1