feat: Initial Terraform Action + Cli

[techman83]

This adds a Terraform Action processor, along with an initial cli printing the generated Stack output.

Example:

(venv) ➜  cally git:(feat/cdktf) cally tf print --stack-name example-stack --stack-type CallyStack
{
  "//": {
    "metadata": {
      "backend": "local",
      "stackName": "example-stack",
      "version": "0.20.4"
    },
    "outputs": {
    }
  },
  "terraform": {
    "backend": {
      "local": {
        "path": "state/example-stack.tfstate"
      }
    }
  }
}