Run the tests in CI

[jbarnoud]

The current CI make the build but does not run the tests. This PR adds a job that runs the tests.

[jbarnoud]

The current issue with this pull request is that some tests are failing. The error seems to be related to loading the ChemicalComponentDictionary; the dictionary's content is passed as a compressed file encoded in base64 and stored in the serialised field of an asset. Loading this asset appears recursive in some cases, making Unity unhappy.

Investigating this part of the code, here are things I notice and should be cleaned up:

• this branch is never run. If it were, it would fail because the path is wrong pointing to Assets/Narupa/Trajectory rather than Assets/Narupa/Frames. (This is fixed now)