Draft: Split into CE/EE image versions

Why is this change being made?

We need to build CE/EE flavours of the image so that we can ship differing Trivy databases within them.

This MR:

• introduces the :5-ee and :5-fips-ee tags (as 5 is the current major version)
• exposes $EE=true within the container and within the script/setup.sh build script

The $EE environment variable gets used to switch on the license type: !2720 (905d5d49)

How to test and validate

• :5:

  docker run --rm registry.gitlab.com/gitlab-org/security-products/analyzers/container-scanning/tmp/trivy:b88b07e575153b6d9cba6ec939486b39d1bb588b sh -c 'echo $EE'

• :5-ee:

  docker run --rm registry.gitlab.com/gitlab-org/security-products/analyzers/container-scanning/tmp/trivy:b88b07e575153b6d9cba6ec939486b39d1bb588b-ee sh -c 'echo $EE'
  true

• :5-fips:

  docker run --rm registry.gitlab.com/gitlab-org/security-products/analyzers/container-scanning/tmp/trivy:b88b07e575153b6d9cba6ec939486b39d1bb588b-fips sh -c 'echo $EE'

• :5-fips-ee:

  docker run --rm registry.gitlab.com/gitlab-org/security-products/analyzers/container-scanning/tmp/trivy:b88b07e575153b6d9cba6ec939486b39d1bb588b-fips-ee sh -c 'echo $EE'
  true

Same goes for Grype, e.g.:

• CE:

  docker run --rm registry.gitlab.com/gitlab-org/security-products/analyzers/container-scanning/tmp/grype:b88b07e575153b6d9cba6ec939486b39d1bb588b-ee sh -c 'echo $EE'
  true