New bot command for updating lists of focus areas

Add a new update-focus-areas command that updates two templates at {{Community Wishlist/Focus areas/All}} and {{Community Wishlist/Focus areas/Top}}. Both are sorted by vote count, and the latter is just the top four.

This doesn't add any focus area data to the database, and the idea of it being separate to the wish-index updating is that the focus areas need to be checked and updated at a different interval (e.g. every few hours?).

Bug: T364648