Adds ability to NumberToHumanSize to style label and hide zero labels

What does this MR do and why?

Adds ability to style <NumberToHumanSize /> component's label (labelClass), and ability to drop labels for 0 values (plainZero).

Screenshots or screen recordings

Before	After

How to set up and validate locally

A storybook story is available! http://localhost:9002/?path=/story/ee-usage-quotas-storage-number-to-human-size--default

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.