FE: Usage Quotas page standardization - Storage

Summary

The goal is to standardize the UI for all the items under the Namespace-level Usage quotas page.

General page design

Scope for this issue is limited to Storage tab https://gitlab.com/groups/groupname/-/usage_quotas#storage-quota-tab

Requirements:

1. update widgets/boxes
2. add bar underneath to show usage progress
3. if no storage limit is applicable, hide the denominator and the bar underneath:

Out of scope:

1. add search bar -> addressed in #351108 (closed)