- Fetches the direct-linked annotation's group when the direct-linked
  annotation's group is not fetched by the group.list, profile.group,
  or the direct-linked group.
- Simplify the logic in the filterGroups function and pass the
  direct-linked annotation's groupid to the filterGroups function to
  avoid a duplicate annotation fetch.
- Add tests.
This is a fix for hypothesis/product-backlog#986.