Refactor protected environments form for approvals

What does this MR do and why?

Adds the ability to display a protected environments approval rules, as well as edit the required approval count.

Also allows for adding and deleting those rules.

Screenshots or screen recordings

How to set up and validate locally

1. Enable the feature flag:

Feature.enable(:multiple_environment_approval_rules_fe)

1. Navigate to a project's environments page Deployments > Environments
2. Add an environment
3. Navigate to the CI/CD settings page Settings > CI/CD
4. Protect the environment
5. View the protected environment
6. add an approver rule
7. edit an approver rule
8. delete an approver rule

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 #378445 (closed)