Implement of job interface to render a project via ARTIST

[fluegelk]

Allow whitelisted users to render their projects via ARTIST, replacing the current, mocked job interface which returns only a dummy status and result.

A rough outline of the steps (to be refined):

• Organizational: HPC access etc
• Implement slurm interaction to submit ARTIST jobs, get the current status, and process the results
• Implement workflow to whitelist users and check user privileges before submitting jobs
• Update and extend the job interface tests