Add unit test to PD 4.0.0 migration function

[IanLondon]

Overview

This will already be covered in E2E from #5369 but I wanted to add unit test coverage to 4_0_0.js migration.

This is a broken-out follow-up to #5373, I didn't want to do it there b/c #5369 is going to move the fixtures all around

[IanLondon]

This should be size 1 but is tricky due to labware definitions getting mocked out in jest, so need to find a solution to that so protocol in matches protocol out for a given labware load name