Add rendering tests with 5ms path

(Generic issue template)

• constants.py:FRAMING_5MS_TO_TEST tests only 20ms framing, this should contain both values. This means currently 5ms is not tested at all.
• The renderer smoke test needs to be updated to remove 5ms xfails too
• MASA external split rendering tests are missing
• (optional) temporary filenames can be updated to avoid multiprocessing collisions