Revert "Support MSC3916 by adding a federation `/download` endpoint" (#17325)

changelog.d/17172.feature

changelog.d/17325.misc

synapse/federation/transport/server/__init__.py

synapse/federation/transport/server/_base.py

synapse/federation/transport/server/federation.py

synapse/media/_base.py

synapse/media/media_repository.py

synapse/media/media_storage.py

synapse/media/storage_provider.py

tests/federation/test_federation_media.py

tests/media/test_media_storage.py