Fixes discharged patients CSV export (#2010)

* Fixes discharged patients CSV export

* default `is_active` to False

care/facility/api/viewsets/patient.py

@@ -410,7 +410,8 @@ def filter_queryset(self, queryset: QuerySet) -> QuerySet:
         if self.action == "list" and settings.CSV_REQUEST_PARAMETER in self.request.GET:
             for backend in (PatientDRYFilter, filters.DjangoFilterBackend):
                 queryset = backend().filter_queryset(self.request, queryset, self)
-            return queryset.filter(last_consultation__discharge_date__isnull=True)
+            is_active = self.request.GET.get("is_active", "False") == "True"
+            return queryset.filter(last_consultation__discharge_date__isnull=is_active)
 
         return super().filter_queryset(queryset)