[cashtab] Agora UI updates

Summary:
Adding some UI improvements to the Agora page.

• More concise header section that aligns the filters
• typography and layout tweaks to the token cards to enhance readability

Test Plan: preview the site and review

Reviewers: #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Subscribers: bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D17502