Sourcing award and return approval by rule

A closed sourcing event can be awarded to its top-ranked response automatically, and a requested return approved, when they are inside the rule's limits.

• Award: the event is past its closing time, the top score reaches the threshold (70 by default), it leads the runner-up by the minimum points in the settings, and its total is within the value limit. The award records that it was made by the rule.
• Returns: the return's reason is on the rule's list (damaged in transit, wrong item, defective by default) and its value is no more than the limit (500 by default). Anything else waits for a person.