[rql2sql/test] Remove dead setUpModule tearDownModule they are overwritten a few lines below , hence this code is dead and not necessary for test success, drop it.

[rql2sql/test] Move base class from repotest to unittest_rql2sql It's only used there, so move it closer to its usage. Along the way, stop using lgc.testlib.

[rql2sql/test] Set maxDiff to None to see full diffs this is usually useful to compare SQL strings