Almost all test scripts currently need to override the __init__()
method. When they do that they need to call into super().__init__() as
the base class does some generic initialization.
This commit makes the base class __init__() call into set_test_params()
method. Individual test cases can override set_test_params() to setup
their test parameters.
dadfee3 [test] Add test for listaddressgroupings (Jimmy Song)
Tree-SHA512: 21cf0233c7fcf585f9a31306612ae1113ea916d2972b834efef0cb2154bd4dd24d9746d0632c778c699328f7e7a336d2da6e2bac9f0fb657c30290757563ad22
