fix to allow integer label refernces

What does this MR do?

this fixes the problems with referencing integer labels as in #38075

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

1. I changed the reference pattern in Label model. will it break anything?
2. Why label id was used in format instead on :name in system_note_service.rb

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

What are the relevant issue numbers?

#38075