Resolves #50 "Get frontend tests working"

Closes #50 (closed)

Notes:

Only works when yarn linking the core-fe package, not as a npm dependency. Not too sure why this is honestly.

Adds the test job to the pipeline. ybc-core-fe has to be on the same level as cs11-main and not frontend because it does not find core-fe's peerDependencies properly, specifically react/jsx-runtime.js. New job takes around 2:30 so will not put us above the 10 minutes allowed (assuming we only take into account the build and test jobs - which currently take a total of 4:30 - and not the deploy stage). Coverage can be calculated through jest, however, we are only allowed one coverage metric per project, so its either python or React, and python is already set up so we might be better to leave it.

Demo:

Pipeline attached to branch