Adding output handler for SARIF JSON format

[alfespa17]

This PR will allow to generate the output using SARIF JSON format when using the following command

node index.js --cloud aws --config ./config.js --sarif=output.sarif.json --console=none --plugin s3Encryption

Basically it just adding a new parameter "sarif=filename"

The output handle will generate the following format:

{
  "version": "2.1.0",
  "$schema": "http://json.schemastore.org/sarif-2.1.0",
  "runs": [
    {
      "tool": {
        "driver": {
          "name": "cloudsploit",
          "version": "3.1.0",
          "informationUri": "https://github.com/aquasecurity/cloudsploit"
        }
      },
      "results": [
        {
          "level": "error",
          "message": {
            "text": "No bucket policy found; encryption not enforced"
          },
          "locations": [
            {
              "physicalLocation": {
                "artifactLocation": {
                  "uri": "arn:aws:s3:::sfqdwr"
                }
              }
            }
          ],
          "ruleId": "S3-S3ENCRYPTION"
        }
      ]
    }
  ]
}

This is a valid SARIF file, check here

Fix #1726

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