Display resource source in JSON output

[eliecharra]

Description
We want to display resource source in JSON output

Example

"differences": [
    {
        "res": {
            "id": "diff-id-1",
            "type": "aws_diff_resource",
            "source": {
                "module": "module.dev_dynamodb_from_omaha_role",
                "name": "main",
                "state": "s3://terraform-state-bucket/accounts/foo.tfstate"
            },
        },

Blocked by #873

[sjourdan]

LGTM

for a missing resource:

  "missing": [
    {
      "id": "driftctl-qa-s3-bucket-2",
      "type": "aws_s3_bucket",
      "source": {
        "source": "tfstate://2/terraform.tfstate",
        "namespace": "",
        "internal_name": "two"
      }
    }
  ],

for a changed resource (deep)

 "differences": [
    {
      "res": {
        "id": "driftctl-qa-s3-bucket-1",
        "type": "aws_s3_bucket",
        "source": {
          "source": "tfstate://1/terraform.tfstate",
          "namespace": "",
          "internal_name": "one"
        }
      },

for a working managed resource

    {
      "id": "driftctl-qa-s3-bucket-3",
      "type": "aws_s3_bucket",
      "source": {
        "source": "tfstate://3/terraform.tfstate",
        "namespace": "",
        "internal_name": "three"
      }
    }