Adding change vulnerability status spec under secure

What does this MR do and why?

This MR introduces a new E2E spec with two test cases to test changing of vulnerability status from a project vulnerability report

Addresses part of: https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1222

How to set up and validate locally

Run against GDK from gitlab/qa using

GITLAB_QA_ACCESS_TOKEN=<XXXX> GITLAB_PASSWORD=<XXXX> QA_DEBUG=true CHROME_HEADLESS=false bundle exec bin/qa Test::Instance::All http://192.168.1.105:3000 ./qa/specs/features/ee/browser_ui/13_secure/change_vulnerability_status_spec.rb

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.