Show environment approvals on deployments page

What does this MR do and why?

This is the beginning of showing deployment approvals historically, as it will show the approval status of all pending, finished, and failed deployments. It does not yet show comments regarding the deployments, only who has approved or rejected the deployment, and how long ago it was.

Changelog: added EE: true

Screenshots or screen recordings

Screencast_2022-04-22_11_24_34

How to set up and validate locally

1. add the following .gitlab-ci.yml to a project for some deployments:

stages:
    - deploy
    - stop
image: alpine:latest

deploy-prod:
    stage: deploy
    script:
        - sleep 6000
        - echo "deploying prod"
    environment:
        name: production

deploy-staging:
    stage: deploy
    script:
        - echo "deploying staging"
    environment:
        name: staging
        url: https://example.com
    when: manual

deploy-review:
    stage: deploy
    script:
        - echo "Deploying review/$CI_COMMIT_REF_NAME"
    environment:
        name: review/$CI_COMMIT_REF_NAME
        auto_stop_in: 1 week
    only:
        - branches
    except:
        - main


stop_review_app:
  script: stop-review-app
  stage: stop
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    action: stop
  rules:
    - if: $CI_MERGE_REQUEST_ID
      when: manual

Run a pipeline to create the initial environments, then protect the staging environment in Settings > CI/CD.

Run another pipeline, and check the environments page.

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.

#355496 (closed)