Show release notes on deployment approval page for tagged deployments

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What does this MR do and why?

Show release notes on deployment approval page for tagged deployments

Closes: #493260

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Before	After
before.mov	after.mp4

How to set up and validate locally

1. Premium licence is required.

2. Navigate to any project.

3. Create a .gitlab-ci.yml file with the following contents:

   stages:
       - deploy
   image: alpine:latest
   
   deploy-prod:
       stage: deploy
       script:
           - sleep 10
           - echo "deploying prod"
       environment:
           name: production
           url: postgres://example.com
       when: manual
   
   deploy-staging:
       stage: deploy
       script:
           - echo "deploying staging"
       environment:
           name: staging
           url: https://example.io
       when: manual

4. Navigate to <project> -> Code -> Tags and create a new release tag.

5. Navigate to <project> -> Deploy -> Releases, create a new release with a description and attach a newly created release tag.

6. Navigate to <project> -> Settings -> CI/CD -> Protected environments and protect one of the environments.

7. Navigate to <project> -> Operate -> Environments, expand a protected environment.

8. Click the Approval options button.