Major Description
We have a non-trivial number of tests that extend LuceneTestCase directly.
For "utility" method minded tests, this is fine - but for any test that wants to instantiate re-use shared config files to instantiate SolrCores, or instances of MiniSolrCloudCluster, this makes these tests really cumbersome to maintain and deal with because htye don't leverage the existing randomization setup logic in SolrTestCaseJ4.
we should fix these tests where applicable