When creating sessions add suitable patients

This means that only patients who go to the school will be added to
school sessions, and only patients with an unknown school will be added
to the community clinic.

Jira-Issue: MAV-1430

Author: thomasleese

app/lib/location_sessions_factory.rb

@@ -53,7 +53,7 @@ def grouped_programmes
   def patient_ids
     @patient_ids ||=
       if location.generic_clinic?
-        team.patients.pluck(:id)
+        team.patients.where(school: nil).pluck(:id)
       else
         team.patients.where(school: location).pluck(:id)
       end

spec/lib/location_sessions_factory_spec.rb

@@ -120,7 +120,7 @@
           session =
             team.sessions.includes(:patients).find_by(location:, academic_year:)
           expect(session.patients).to include(patient_at_location)
-          expect(session.patients).to include(patient_at_school_location)
+          expect(session.patients).not_to include(patient_at_school_location)
         end
       end
     end