Add Dependency Scanning to Dependency List - Add vulnerabilities to response

Backend part of #10077 (closed)

Implementation plan:

• Update parser to include an array of vulnerabilities for each dependency https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14706
• Update serializer to support parser changes https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14761#note_194136441