Improve usage loading spinner style

[gtsiolis]

Problem to solve

Back in #11687, a loading indicator (spinner) was added while the data is loading. Thanks, @laushinka and @easyCZ!

Although, there are no concrete guildelines yet on the loading indicators (spinners), we've been using a slightly different pattern for the loading spinner for fetching data-heavy pages.

Branches	Prebuilds	Usage

Proposal

Update the loading indicator (spinner) of the usage page to follow the style of the rest of the instances across the product.

Things to consider:

1. Align horizontally loading spinner with the loading text.
2. Use sentence case instead of uppercase.
3. Use the same top margin from the header.

[kradchenko]

Hi @gtsiolis! I would like to work on this issue!

[gtsiolis]

You're welcome, @kradchenko! Feel free to mention this issue once you open a pull request to resolve this. 🏓