Fix bug where jobs had the opposite of the intended priority. Populating saved searches had the
highest priority, while processing uploads had the lowest priority.
Caused by Delayed::Job and GoodJob having opposite interpretations of job priorities. In
Delayed::Job, lower numbers had higher priority, while in GoodJob, higher numbers have higher
priority. This was missed when migrating from Delayed::Job to GoodJob.
* Don't delete the user's favorites unless private favorites are enabled. The general rule is that
public account activity is kept and private account activity is deleted.
* Delete the user's API keys, forum topics visits, private favgroups, downvotes, and upvotes (if
privacy is enabled).
* Reset all of the user's account settings to default. This means custom CSS is deleted, where it
wasn't before.
* Delete everything but the user's name and password asynchronously.
* Don't log the current user out if it's the owner deleting another user's account.
* Fix#5067 (Mod actions sometimes not created for user deletions) by wrapping the deletion process
in a transaction.
