Resolve "Add internationalization support for the Prometheus Merge Request widget"

What does this MR do?

Adds i18n for the MR Widget, to be more specific, the memory performance part of it

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessar
• Review
  • 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 #44218 (closed)