Add job to record/report all final images and tags

What does this MR do?

Add final-image-listing job, in final-list stage.

• "final" images are added as an array
• job uses needs based on .final_images content
• build.sh loads content from ci_files/final_images.yml into an array
• push_tags function adds is_final_image check for branch pipelines, which then records to artifacts/final/

In support of !710 (merged)

Related issues

https://gitlab.com/gitlab-com/gl-security/appsec/appsec-team/-/issues/149

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Integration tests added to GitLab QA
• The impact any change in container size has should be evaluated