Reintroduces the usage quota page data-testids

What does this MR do and why?

Reintroduces the data-testids that were removed by !129454 (merged) and caused free_namespace_storage_spec to fail.

Related: #422570 (closed)

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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