Update free namespace spec to test various storage types

What does this MR do and why?

This MR updates the spec from a basic test to see if the storage size count increments to testing the various storage types and ensuring the total adds up properly.

Related: #416569 (closed)

How to set up and validate locally

Run the test against staging. bundle exec rspec qa/specs/features/ee/browser_ui/11_fulfillment/utilization/free_namespace_storage_spec.rb

Because there's new data-testids being introduced here and the test can only be run against Staging, a breakpoint will need to be introduced right before the individual storage sizes elements are verified in order to manually add the data-testid required to locate these elements.

1. Add binding.irb before the individual storage sizes elements are verified after the aggregate_failures do in qa/qa/specs/features/ee/browser_ui/11_fulfillment/utilization/free_namespace_storage_spec.rb.
2. Run the spec against Staging.
3. Once it hits the breakpoint, modify the DOM to add the data-testids.
   • I look up where it is in the DOM by inspecting the Repository storage size
   • The data-testids that need to be added are:
     1. data-testid="project-repository-size" for the Repository size
     2. data-testid="project-snippets-size" for the Snippets size
     3. data-testid="project-wiki-size" for the Wiki size
     4. data-testid="project-containers-registry-size" for the Containers size
4. Once those data-testids are added, you can continue the test with exit command to get the test going again.

MR acceptance checklist

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