Support destroy action for a Terraform object not attaching to a Source

[chanwit]

A Terraform object is not guaranteed to permanently attach to a Source. In some scenarios, the Source is deleted before deleting the Terraform object.

Fortunately, terraform destroy can be run against a Terraform state to delete all of its resources. In order to do so, we will improve the semantic of destroyOnDeletion to destroy directly with the state file, without planning or applying.