Chunk dependant wallclock time

Also from the new monitoring tool, we will start facing jobs that require much higher wallclocks as the chunk number growths. It will be nice to have the ability to increment the wallclock of the job based on the chunk number, for example to submit the job with a wallclock of 10:00 + 5:00 * CHUNK.

It is not critical at all, but may save us a bit of queue time not having to put the maximum wallclock for the first jobs