Update issuable status icons

What does this MR do?

• Update issuable status icons

.	Before	After
Issues
Merge Requests

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

Should issue closed be blue (primary)? It was blue in the before design from the issue so I updated it and makes sense that it is a resolved color.

Changed new/removed/modified file icons are already up to date (modified is a bit different but it is using what is available in the gitlab-svgs repo). Updated in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15367

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• 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

What are the relevant issue numbers?

Closes #33926 (closed)