Add support for terraform security best practices checks (Checkov)

[schosterbarak]

Consider adding Checkov.
Checkov now has a documented pre-commit integration:
https://bridgecrewio.github.io/checkov/4.Integrations/pre-commit.html

pre-commit configuration is available at:
https://github.com/bridgecrewio/checkov/blob/master/.pre-commit-hooks.yaml