This patch improves branch coverage of the test, making sure a
message can not be verified with the wrong address or signature.
Github-Pull: #11241
Rebased-From: b3d6fc654770e3b4d2f82e8d77e531df9e522982
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.
Github-Pull: #11121
Rebased-From: 5448a1471d6fc638a2220ea5a2f3782172efe14c
