Truncation for summaries

As summaries can get a bit long for certain formats we want to truncate them at a natural end.

This PR does this by gsub everything after a full stop followed by a space and an uppercase letter. This functionality can't be achieved with the normal truncate helper because it works by finding the separator
before the limit, but we wanted it to find the first separator after the limit.

This way we have a more natural text break, which should hopefully get around the need for a hard limit.

This PR also enables summaries for Drug Safety Updates and International Developer Funds.

[Ticket](https://trello.com/c/mcB4awdn/479-show-summaries-for-the-alerts-and-recalls-for-drugs-and-medical-devices-finder-1)