Adding SARIF support

[shaopeng-gh]

Add support for output in SARIF format.

Hello! We are interested in adding support for output in the open-standard SARIF format to speccy. SARIF support is required to integrate it in GitHub code scanning. Doing so would make it available to every repo in GitHub and could result in increase in user base.

More about SARIF here: What is SARIF? Why SARIF?

After the support for SARIF output is added to the tool and published a new version, we will work on creating a starter workflow to make it available as a GitHub code scanner.

[shaopeng-gh]

@yongyan-gh @eddynaka @EasyRhin0

[shaopeng-gh]

@djtarazona please review, thanks!