Support -destroy option for terraform apply >= Terraform CLI 0.15

[rstandt]

Post Terraform CLI 0.15, terraform apply -destroy can be used in place of terraform destroy. This issue proposes allowing the DestroyFlagOption to be passed to (tf *Terraform) Apply to replicate this direct terraform CLI usage behavior.

Proposal

Implement the ApplyOption interface for the DestroyFlagOption
Add the -destroy flag to the (tf *Terraform) Apply unit test
Add an e2e test which replicates TestDestroy using the new functionality