Show copy for storage limits in Self-Managed

What does this MR do and why?

This is part of a fix for https://gitlab.com/gitlab-org/gitlab/-/issues/425109. After !133016 (merged) got merged, while validating it, it was noticed that we could show another piece of text for Self-Managed customers if they have setup repository limits in their instance. This MR aims to fix that.

It also fixes the wrongly shown purchased storage information in the card. Purchased storage only applies to SaaS.

Screenshots or screen recordings

Before (With or without limits)	After without limits	After with limits

How to set up and validate locally

The UI changed is accessed by https://gdk.test:3443/groups/<my-group>/-/usage_quotas#storage-quota-tab

• Replace my-group with your group id 😉

1. Make sure you're NOT simulating SaaS in your GDK
2. Access your Group Usage Quotas Page
3. Make sure you see the no limits applied copy
4. In rails console, add a repository size limit:
   1. Gitlab::CurrentSettings.update!(repository_size_limit: 10.gigabytes)
5. Back to the browser, inside the left-hand side card, check for the copy: 10.0 GiB Storage per project included in Free subscription

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.