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.
We can call gettxoutproof() with a list of transactions. Currently, if
the first transaction is unspent (and all other transactions are in the
same block), then the call will succeed. If the first transaction has
been spent, then the call will fail. The means that the following two
calls will return different results:
gettxoutproof(unspent_tx1, spent_tx1)
gettxoutproof(spent_tx1, unspent_tx1)
This commit makes behaviour independent of transaction ordering by looping
through all transactions provided and trying to find which block they're in.
This commit also increases the test coverage and tests more failure
cases for gettxoutproof()