Add SARIF support

It would be nice to be able to format output as [SARIF](https://docs.oasis-open.org/sarif/sarif/v2.1.0/sarif-v2.1.0.html). Then it can be used with [GitHub Code Scanning](https://docs.github.com/en/code-security/code-scanning/integrating-with-code-scanning/sarif-support-for-code-scanning).