EE Port of Multif File Editor File Icons

What does this MR do?

Adds Icons to Multi FIle Editor File Icons - Port of gitlab-org/gitlab-ce!16100

Does this MR meet the acceptance criteria?

• 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

What are the relevant issue numbers?