* Add command interface and implementation for disabling organizations
* Register organization disable command for dependency injection
* Add unit tests for OrganizationDisableCommand
* Refactor subscription handlers to use IOrganizationDisableCommand for disabling organizations
* Remove DisableAsync method from IOrganizationService and its implementation in OrganizationService
* Remove IOrganizationService dependency from SubscriptionDeletedHandler
* Remove commented TODO for sending email to owners in OrganizationDisableCommand
