Add vendored template tests for DAST

Add an end to end test that uses the current DAST template against the latest DAST scanner.

The end to end test has been setup in this project. https://gitlab.com/gitlab-org/security-products/tests/dast-e2e

Old Description

As we release new versions of DAST, its possible that historical versions of gitlab-ci.yml files no longer work with DAST.

We should setup a repo that maintains historically supported CI files and ensure that those templates continue to work.

A sample repo has been configured here: https://gitlab.com/sethgitlab/dast-template-tests

There are open MRs in the repo to illustrate each template working.

This repo should be moved into an official GitLab repo that is added to the DAST release pipeline.