Increase all TRAIT LOCK minimum runtimes to 21 days (504 hours)

Currently, the minimum runtime for a TRAIT LOCK proposal is 7 days or 168 hours. I'd like to increase this window to a 21 day 504-hour minimum, so that anytime a trait lock is proposed, the community can rally to focus on that trait in the short term and have sufficient time to submit final proposals to classifications specific to that trait.

As it currently is, a trait lock proposal could be submitted on a 7-day schedule, which would effectively block any new updates from being passed before the trait was potentially locked.