Convert dynamic zone test cases to pytest

Convert dynamic zone test cases to pytest

This commit deals with converting the dynamic zone test cases to
pytest. The tests for 'inline-signing.kasp' are similar to the default
case, so these are added to 'test_kasp_default'.

Unfortunately I need to add sleep calls in between freezing, updating,
and thawing a zone. Without it the intermittent failures are too
frequent.