Use `haml_lint` for views linting

What does this MR do?

Add HAML-linting to the GitLab codebase.

Are there points in the code the reviewer needs to double check?

• I've enabled the linters that currently have 0 offenses (see the list in #22072 (closed)).
• Other linters will be enabled in separate merge requests.

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Documentation created/updated
• Tests
  • Added for this feature/bug
  • All builds are passing
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #19984 (closed).