[Cashtab] Show token qty and cumulative qty in any given agora offer in a tooltip

Summary:
Part of incremental effort to get agora UX on par with binance UX

Both Binance and Coinex show the amount of token for sale at each limit order price. They also show the cumulative amount as you proceed further up the depth chart.

I think it is too much info to show these quantities all the time in Cashtab, esp as token quantities can be quite large. But would be nice to show with a tooltip.

Expanding on D17449 which I forgot about

Test Plan:
npm test for CI, screenshot to confirm we see displayed amount. The calculation of the amount itself is already tested elsewhere.

...for some reason the opacity goes down when I take a screenshot, but it is not like this in normal use, can verify at test site

deployed to test site at https://cashtab-local-dev.netlify.app/

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D17540