Support freezing media on the unauthenticated endpoints (#600)

CHANGELOG.md

api/_apimeta/auth.go

api/r0/download.go

api/r0/thumbnail.go

api/routes.go

api/v1/download.go

api/v1/thumbnail.go

archival/entity_export.go

common/config/conf_main.go

common/config/models_main.go

common/errors.go

config.sample.yaml

database/db.go

database/table_restricted_media.go

migrations/29_create_media_restrictions_down.sql

migrations/29_create_media_restrictions_up.sql

pipelines/pipeline_download/pipeline.go

pipelines/pipeline_thumbnail/pipeline.go

pipelines/pipeline_upload/pipeline.go

restrictions/auth.go