Dogfood new direction for Code Quality in gitlab-org/gitlab

Proposal

Rework how Code Quality is used in gitlab-org/gitlab to reflect &8790 (closed) (and based on its approach).

• Remove the template: Jobs/Code-Quality.gitlab-ci.yml import and relevant job configuration from its current place.
• Add artifacts:reports:codequality output to existing static analyzers used in the build:
  • Rubocop
  • eslint
  • haml-lint

These configs (especially the code_quality job and template import) don't appear to get heavy development—very few changes in the past couple of years.