Draft: Add OTC card to usage billing app

What does this MR do and why?

It adds on time credits (waiver) card to the usage app, it will be shown when there's a any OTC credits.

note: depends on Update subscriptionUsage query (!209845)

References

Screenshots or screen recordings

Before	After
	(please ignore the fact that there are 4 cards, others will be toggled later

How to set up and validate locally

• yarn storybook:start
• Navigate to http://localhost:6006/?path=/story/ee-usage-quotas-usage-billing-app--with-otc-credits

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #577984