Minor fix and sonar bits and bobs

Author: dlzhry2nhs

backend/src/authorisation/authoriser.py

@@ -65,8 +65,8 @@ def filter_permitted_vacc_types(
         types that they cannot interact with without throwing an error"""
         supplier_permissions = self._get_supplier_permissions(supplier_system)
 
-        return set([
+        return {
             vaccine_type
             for vaccine_type in vaccination_types
             if requested_operation in supplier_permissions.get(vaccine_type.lower(), [])
-        ])
+        }

backend/src/fhir_service.py

@@ -324,7 +324,7 @@ def search_immunizations(
         # TODO: is disease type a mandatory field? (I assumed it is)
         #  i.e. Should we provide a search option for getting Patient's entire imms history?
         if not nhs_number_mod11_check(nhs_number):
-            return create_diagnostics()
+            return create_diagnostics(), False
 
         permitted_vacc_types = self.authoriser.filter_permitted_vacc_types(
             supplier_system, ApiOperationCode.SEARCH, set(vaccine_types)