Rename 'SAST:container' to 'Container Scanning'

Description

SAST:containers seems like a lame name and it will need to change as we adopt SCA. Can we change that into 'Container scanning' as used by https://www.sonatype.com/native-container-analysis and https://cloud.google.com/container-registry/docs/vulnerability-scanning?

Proposal

Places to be updated:

• Documentation
• Pricing page
• Technical elements naming (job, artifact, functions)

Note: Technical renaming won't include job artifact filename as there is currently no easy way to implement backward compatibility. Job name should handle both the new container_scanning and the old sast:container possibilities.

Links / references

• From https://gitlab.com/gitlab-org/gitlab-ee/issues/4967#note_59415340