Remove approvals when in empty MR widget state

What does this MR do?

CE backport, https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15362

• Remove approvals when in empty MR widget state

Before	After

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

• Where should the EE tests go?
  • Discussion in #fe-architectural, https://gitlab.slack.com/archives/C4GFEUG90/p1510607140000023

Why was this MR needed?

When showing the empty state in the MR widget, it shouldn't have other sections displayed

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• If paid feature, have we considered GitLab.com plan and how it works for groups and is there a design for promoting it to users who aren't on the correct plan

What are the relevant issue numbers?

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/39009