[ENH] Add unit tests for REST API Endpoints

[smokestacklightnin]

Feature description

Currently, the only unit tests for REST API endpoints we have are from #547.

We should have unit tests for all the endpoints.

Value and/or benefit

No response

Anything else?

If anyone wants to take this issue over, feel free.

[staru09]

Is this available to take?

[pmeier]

Hey @staru09 👋 Thanks a lot for wanting to contribute. However, we are currently not sure what will happen to this project. The landscape has changed significantly since we started to work on Ragna. I don't believe it offers a lot of value as is right now. Meaning, we are not working on Ragna until we made a decision to either pivot the direction or archive it. Regardless, for you this means that contributing at this time is rather pointless. We won't devote resources to review any contributions.