Context

adding workflows for domain deployment to build workflows

Changes proposed in this pull request

updated deploy.yml adding calls to the deploy domains github actions.
output.tf is added to provide external_urls for testing

Guidance to review

checkout branch and run the following

make test domains-plan 
make preprod domains-plan 
make production domains-plan 
make domains-infra-plan

verify the external urls are correct.

in browser check health check url

https://www.access-your-teaching-qualifications.education.gov.uk/health

verify the code in the github action
verify the list of domain_environments is correct

Link to Trello card

Implement CI/CD for domains on all services