[FE] UI for display validity check on MR Security Widget

Problem to solve

Add a new “Validity Check” section to the existing MR security widget. For each finding, render the token status badge alongside a hover tooltip, matching the styles used in the Vulnerability Report and pipeline security tab.

Proposed Solution

#479341[validity_in_modal.png]

Follows much the same logic as the Vulnerability Details page.

Implementation Plan:

• %18.3 - Add the validity check permission to the MR modal
  • See spike: !200672 (closed)
• %18.3 - Implement UI-only for the token badge
• %18.4 - API integration for the token badge (need to wait for BE to complete) -- to be implemented in this issue [FE] API Integration for the validity check in ... (#561068 - closed)