Resolve "Group security issues panels in the MR widget"

What does this MR do?

Adds new row components needed for: https://gitlab.com/gitlab-org/gitlab-ee/issues/4310

1. Loading Row
2. Error Row
3. Summary Row
4. Help popover component https://gitlab.com/gitlab-org/gitlab-ee/issues/4464

loading
Spinner icon + in progress

error
Exclamation mark icon + There was an error in loading results

Note: Aligments will be done in the major issue

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• 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
• End-to-end tests pass (package-qa manual pipeline job)

What are the relevant issue numbers?

#4310 (closed) https://gitlab.com/gitlab-org/gitlab-ee/issues/4464