Add unit tests to the backend

[KINGTUT10101]

Right now, only the frontend components have unit tests. We need to add some unit tests to the backend after the new API is implemented and change the workflow to test in the backend folder too.

[KINGTUT10101]

This would probably require us to create a small database on the workflow runner with some mock data. I think this is outside the scope of this project, so we can probably ignore it for now