Refactors Usage Quotas feature specs to be located under one folder

What does this MR do and why?

This is a first step in Refactor Usage Quotas feature specs to have ded... (#381108 - closed)

This MR starts reorganisation of Usage Quotas feature specs, it moves related files under one folder (ee/spec/features/groups/usage_quotas/), renames the files, and fixes all Rubocop formatting and naming rules.

Screenshots or screen recordings

n/a

How to set up and validate locally

rspec ee/spec/features/groups/usage_quotas/

MR acceptance checklist

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