TMSS-2027: adaptations to get the migrations working again with this new major django version

SAS/TMSS/backend/src/tmss/tmssapp/migrations/0001_initial.py

...rc/tmss/tmssapp/migrations/0005_remove_obsolete_fields.py

...S/backend/src/tmss/tmssapp/migrations/0007_systemevent.py

...ss/tmssapp/migrations/0013_add_processing_feedback_doc.py

...S/backend/src/tmss/tmssapp/migrations/0049_cyclereport.py

SAS/TMSS/backend/src/tmss/tmssapp/models/common.py

SAS/TMSS/backend/src/tmss/tmssapp/models/permissions.py

SAS/TMSS/backend/src/tmss/tmssapp/models/scheduling.py

SAS/TMSS/backend/src/tmss/tmssapp/viewsets/lofar_viewset.py