[17.0] [IMP] fieldservice_recurring: optimize order generation logic

[brian10048]

I experienced an issue with the field service recurring cron task that generates new orders. A memory limit was reached and the task would fail to execute in some databases that have some fsm_recurring records with a high number of linked fsm_order records

It would always hang in this block of code

        for order in rec.fsm_order_ids:
            if order.scheduled_date_start:
                order_dates.append(order.scheduled_date_start.date())

The order_dates list was used to prevent creating new orders on a date which there already exists an order. However, we do not need to even consider all these dates in the past

This change removes the order_dates list. Instead, the first element of the rruleset is skipped if an order already exists in the recurring. This date is the same as the 'dtstart' parameter which is derived from the last scheduled order

[OCA-git-bot]

Hi @wolfhall, @max3903,
some modules you are maintaining are being modified, check this out!