BoardJobPost possibly needs a copy of datetime and status fields

[jace]

Loading jobs currently requires a join and sort between BoardJobPost and JobPost, as the first decides what's included, and defines a sort order based on the pinned column, while the second provides status and datetime which are used to exclude older posts, and as a secondary sort key.

If datetime and status are replicated in BoardJobPost, we'll no longer need the join to filter and sort. The join is then only to fill in details. datetime is set only twice, (a) when the draft is created and (b) when it's confirmed. It's never changed after that. status changes more often, but also under controlled conditions. Unfiltered index page performance will improve with this.

[jace]

Deprecated by #418.