run_OQStandard.sh should do the hazard calculation only once per scenario

[anthonyfok]

The run_OQStandard.sh script needs to be optimized to avoid repeated identical hazard calculation. The ideal behaviour, as envisioned by @tieganh, is to make only one hazard calculation per scenario, and to refer to that same haz calc for the damage baseline, damage retrofit, risk baseline, and risk retrofit calculations.

@tieganh explained in more details in #86 (review):

… The reason to get rid of running the haz calc was because I changed how I used it in my workflow for the most part. The damage and risk calculators need a hazard calculation, so either you give them the name of one or they will do the calculation internally. Since we run both baseline and retrofit scenarios, my goal was to redo this script so that it would do the hazard calc only once and then use the '-hc' flag (need to double check this, just going off memory) in the damage and risk calculators to point them to that hazard calculation for baseline and retrofit. However, I don't think I got to that point. I only made it so it shares one haz calc for the baseline and retrofit of each calculator type (dmg and risk). I also just started skipping the hazard calc since it wasn't needed for some calculations.

I'm really open to your feedback about the best way to proceed, and have approved the changes as is. If you've got some bandwidth to change this script to do the ideal behaviour (1 haz calc per scenario and call to it for the damage baseline, damage retrofit, risk baseline, and risk retrofit calculations) then that would be the best outcome. …