Integrate docker build and first startup test

[ebroda]

Description of the issue

There sometimes issues with the docker image and it's build process which are introduced as things change and the docker generation and startup process is not always tested by the devs.

Ideas of solution

Include an automated github check, at least for merge requests, which builds the docker image and trys to start it. If the image hasn't thrown error after like a minute (which is probably enough to test it), then this can be assumed as passed.

Alternatively, try to do a get on localhost:8080, which should succeed when the container started successful.

I'm not sure of how to do that, but probably there's a CI way to do that.

Workflow checklist

• I am aware of the workflow in CONTRIBUTING.md

[jh-RLI]

Good idea, i would have to look into it again but i set up similar things in the past. Maybe it is better to go the alternative way you suggested.