Add a License Scanning E2E spec

What does this MR do and why?

Describe in detail what your merge request does and why.

Add a License Scanning E2E spec

This uses Dependency Scanning to populate license information

It targets Staging for the following reason:

• License data needs populated from the new License DB, which it is already on Staging.
  • I looked into being able to set this on a local environment, it involved in rails console:
    • setting PM_SYNC_IN_DEV to true
    • running PackageMetadata::SyncWorker.new.perform
    • However I then found my licenses were 'unknown'

How to set up and validate locally

Pre-requisite:

• Needs ran on an x86-64 box with Docker installed. This is due to the test live-running Gemnasium as a job.
  • UPDATE: I've found running colima can run locally on an M1

Target Staging:

• Unset EE_LICENSE if set
• Run from qa directory
  • <usual staging env variables> bundle exec bin/qa Test::Instance::All https://staging.gitlab.com qa/specs/features/ee/browser_ui/13_secure/license_scanning_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.