Max 1 queued job

No more than 1 job should be placed in the dispatch queue at a time
Issues: NARC-11  

The number of HarvestJobs queue for processing should be minimized at a given time for the following reasons:

• When the HarvestJobManager is restarted, all queue jobs are resubmitted which will cause dublicate processing of the HarvestJobs
• Modifing HarvestDefinitions will not have an effect on queue jobs.

Test specification

Create 4 selektive harvest jobs

Because only 2 selective harvesters (high-priority) are available, only 2 of the jobs should be started initially (one pr. HIGH_PRIORITY harvester). The remaining two jobs should remain in state 'New' until a harvest finishs and the next job is started.

Wait for the first job is done (with 5 minutes timeout)