Variable slurm priorities for jobs

[talnor]

What needs to be done:
Currently all jobs are submitted to slurm with highest priority, which is not always correct.

Suggestions on how to get it done:
Set the priority for all jobs in a case based on the highest priority sample in that case (this avoids delaying high prio samples due to low prio samples being in the same case). Priorities are available in the case config input for each sample ("priority").

What are the arguments for getting it done:

Task is considered finished when:

• slurm job priority is set variably as described above.