district: Fix migrations so they work on clean installation

...grations/0037_districtcrossroadpage_districtcustompage.py

district/migrations/0038_auto_20220303_1107.py

...ions/0050_alter_districtcrossroadpage_content_and_more.py

...rations/0054_alter_districtcenterpage_content_and_more.py

...ations/0055_alter_districtarticlepage_content_and_more.py

...rations/0055_alter_districtcenterpage_content_and_more.py

...ations/0061_alter_districtarticlepage_content_and_more.py

...ations/0066_alter_districtarticlepage_content_and_more.py

district/migrations/0067_delete_all_superseded_pages.py

.../migrations/0087_delete_all_districttagspage_instances.py