Simplify ability to get state JSON from state affecting subcommands

Here is the upstream issue to simplify this interaction: https://github.com/hashicorp/terraform/issues/25467

Ideally we would be able to do something like `terraform apply -state-out-json foo.json` and just read that file with the `terraform-json` module. We could then use this in the methods to return the state (ie. `Apply(...) (*tfjson.State, error)`)