Adds suffix to enum methods and changes `in_groups` to
`of_groups`

Both of these were related to groups:

1. We need to preload routes (using the `with_route` scope) if we're
   going to get the group's path.
2. We were counting each group's members separately.

They're in the same commit because the spec for N+1 detection wouldn't
pass with only one of these fixes.

For directories application_settings --> labels.

Partially addresses #47424.