To prep for the addition of the freeze wizard:
* move projects out of `pull_requests.py`
* then realize half the methods there have no relation to projects and
move them to more relevant places in `pull_requests.py`
* update corresponding crons (and tests using those crons) as the
methods have changed model, and the cron definitions thus need to be
updated
* split update to labels out of sending feedback comments while at it:
labels are not used much during tests so their manipulation can be
avoided; and labels are not as urgent as feedback so the crons can
be quite a bit slower
* move the project view out of `mergebot.xml` as well
