Working Trivy checks here.

I have few questions to prepare the final PR:

1. What behaviour is expected - fail on error or produce the info without workflow errors?
2. What output is expected - print table results in the console log of the workflow or upload it to the GitHub Security tab of the repository.

The code in this PR provides the "maxi" version - with the upload of the results to the security tab. But I'm not sure whether currently the size of the security checks hits the upload limit of 1000 lines or not. :)
I tested it in my fork:

• checks - https://github.com/ihormkl/xnat-docker-compose/pull/1/checks
• results - https://github.com/ihormkl/xnat-docker-compose/security/code-scanning?query=ref%3Arefs%2Fpull%2F1%2Fmerge