DAST URL MR widget modal - Frontend

Main issue

This is a frontend sub-issue for #220405 (closed)

Implementation

• Create a re-usable modal as per the design ☝
• Use the GraphQL endpoint to fetch the details and populate the modal
• Make the download CSV button work based upon #220407 (comment 357745321)
• Smart truncation of URLs when gitlab-ui#767 (closed) is ready

Testing

• Test MR with and without DAST scanned URLs
• Verify downloadable links for expired artifacts