* Add spec for unblock domain service

* Refactor UnblockDomainService

* Set domain_block by before_action

* Cast value with ActiveRecord::Type

* Batch update

Create MediaAttachment but without actual file download when domain is blocked with reject_media set to true
Clean up old media files when creating a new domain block with reject_media set to true
Return remote_url in media attachments API if local file is not present
Undo domain block action in admin UI
Ability to enable reject_media from admin UI