Add empty deployment component

What does this MR do and why?

This sets up the deployment space to allow the addition of all the deployment details later on.

Screenshots or screen recordings

It is currently not very exciting, but you can see the grey strips that map to the latest and upcoming deployments per environment

How to set up and validate locally

Make sure to turn on the new_environments_table feature flag. On the GitLab repository, run:

cd ./bin 
./rails console
Feature.enable(:new_environments_table) //turns on the feature flag
Feature.disable(:new_environments_table) //turns off the feature flag, takes some time to kick in

Then 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 and check out 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.

For #343029 (closed)