New endpoint to import a Transkribus collection

.gitlab-ci.yml

arkindex/dataimport/api.py

...ex/dataimport/migrations/0017_dataimport_collection_id.py

arkindex/dataimport/models.py

arkindex/dataimport/serializers/imports.py

arkindex/dataimport/tests/test_transkribus_import.py

arkindex/documents/models.py

arkindex/project/api_v1.py

arkindex/project/config.py

arkindex/project/default_corpus.py

arkindex/project/openapi/patch.yml

arkindex/project/settings.py

arkindex/project/tests/config_samples/defaults.yaml

arkindex/project/tests/config_samples/override.yaml

arkindex/users/admin.py

arkindex/users/api.py

arkindex/users/migrations/0005_user_transkribus_email.py

arkindex/users/models.py

arkindex/users/serializers.py

arkindex/users/tests/test_providers.py