Convert keystore and rumoured kasp test cases

Convert keystore and rumoured kasp test cases

For 'keystore.kasp', a setting 'key-directories' is used. If set, this
will expect a list of two directories, the first one is where the KSKs
will be stored, the second in the list is the ZSK key directory. This
may be expanded in the future to test more complex key storage cases.

The 'rumoured.kasp' zone is weird, the key timings can never match
those key states. But it is a regression test for an early day bug,
so we convert it, but skip the expected key times check.