Fix up some notes.js tech debt

What does this MR do?

EE MR: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1911

Fix up tech debt comments from @jschatz1 in notes.js. The bulk of the fixes here are refactoring double-quotes to single-quotes.

• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10837#note_28757436
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10837#note_28757905
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10837#note_28757952
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10837#note_28758013

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

Does this MR meet the acceptance criteria?

• Tests
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together