setup CodeQL workflow

[mmorel-35]

Same as in https://github.com/containernetworking/cni

This will improve "SAST" scoring on https://securityscorecards.dev/viewer/?uri=github.com/containernetworking/plugins as scorecard cannot identify it if it's activated in the settings of the project in Github.

[github-advanced-security[bot]]

This pull request sets up GitHub code scanning for this repository. Once the scans have completed and the checks have passed, the analysis results for this pull request branch will appear on this overview. Once you merge this pull request, the 'Security' tab will show more code scanning analysis results (for example, for the default branch). Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results. For more information about GitHub code scanning, check out the documentation.

[MikeZappa87]

@mmorel-35 are you able to rebase this to resolve the conflicts?

[mmorel-35]

That's rebased, just needs approval

[mmorel-35]

@MikeZappa87 , @squeed , Would you be able to review/approve this ?