Add E2E test to verify storage usage in pooled repos

Description of the test

Test case to verify that the reported storage usage is accurate for repositories, including those using pooled storage. https://docs.gitlab.com/ee/administration/repository_storage_types.html#hashed-object-pools

https://gitlab.com/gitlab-org/gitlab/-/quality/test_cases/366599

- Create a Project
- Add 50kb file to Project
- Fork Project (In the background - pools will be setup to share data between the 2 projects)

- Add 40kb file to Project
- Add 30kb file to Project-Fork
- Trigger HouseKeeping, and RepositorySize Checks to get an updated RepoSize value

- expect Project Size to be 0 kb --> All data in source project is moved to the pools
- expect Project-Fork Size to be ~30kb --> The original 50kb is in the pools and not counted, but the 30kb unique to the project is counted

How to set up and validate locally

From the qa directory:

bundle install
bundle exec rspec <pqa/specs/features/api/3_create/repository/storage_size_pooled_spec.rb

Checklist

• Confirm the test has a testcase: tag linking to an existing test case in the test case project.
• Note if the test is intended to run in specific scenarios. If a scenario is new, add a link to the MR that adds the new scenario.
• Follow the end-to-end tests style guide and best practices.
• Use the appropriate RSpec metadata tag(s).
• Most resources will be cleaned up via the general cleanup task. Check that is successful, or ensure resources are cleaned up in the test:
  • New resources have api_get_path and api_delete_path implemented if possible.
  • If any resource cannot be deleted in the general delete task, make sure it is ignored.
  • If any resource cannot be deleted in the general delete task, remove it in the test (e.g., in an after block).
• Ensure that no transient bugs are hidden accidentally due to the usage of waits and reloads.
• Verify the tags to ensure it runs on the desired test environments.
• If this MR has a dependency on another MR, such as a GitLab QA MR, specify the order in which the MRs should be merged.
• (If applicable) Create a follow-up issue to document the special setup necessary to run the test: ISSUE_LINK
• If the test requires an admin's personal access token, ensure that the test passes on your local environment with and without the GITLAB_QA_ADMIN_ACCESS_TOKEN provided.