bot: add pages to aggregate message group after marked for translation

Historically this was done by CWS Manager (now WishlistManager) but it's better handled by the bot. This MR looks for pagetranslation/mark events of wish pages in recent changes, and adds them to the aggregate message group (shown at Special:AggregateGroups and also Community Wishlist/Translation). This aggregate group is a means for translators to go to one place for translating wishes. It may later be further categorized by focus area if the wishes group gets too big.

The new addPageToAggregateGroup() method is added as a static and class member of BotCommand. We don't want to use the Util class for example, because that is used by WishlistIntake and this backend-only code should not ship with the gadget.

Also fix linting error in BotCommand