Implement Trivy code scanning to help identify vulns

[ARolek]

@fjrsaracho surfaced an issue reported by the code scanning tool Trivy. This issue is about implementing Trivy to do a scan weekly so we can stay on top of vulns even if code is not being pushed.

It is under Apache License 2.0. Including comercial usage. You can read more on following link: https://github.com/aquasecurity/trivy/blob/main/LICENSE

Not sure if it fits for you as a real "open-source"

Originally posted by @fjrsaracho in #1000 (comment)

[iwpnd]

Github offers code scanning too natively if that is an option.

[ARolek]

@iwpnd yeah they do, via CodeQL. From my understanding Trivy and CodeQL overlap, but also cover different parts of the codebase. CodeQL would cover the Go and JS code, and Trivy covers the Dockerfile. I still need to research some of the details, but this is my high level understanding.

[iwpnd]

For docker we should be able to get away with Dependabot keeping the image updated.