finish ecomail newsletters

district/migrations/0316_alter_districtcustompage_content.py

district/models.py

.../0154_mainhomepage_ecomail_newsletter_list_id_and_more.py

main/models.py

shared/blocks/parents/struct.py

shared/models/main.py

shared/utils.py

shared_legacy/blocks/base.py

...rations/0127_alter_uniwebflexiblepage_content_and_more.py