[Cashtab] Deprecate the rest of antd

Summary:
T2207

Remove last antd stuff

Bundle is now just under 705kb, which is a good improvement (we were over 1mb for awhile). Will keep picking away at it.

Summary

• All icons are now imported image files
• We have our own spinner
• Improve appearance of Wallets and Contacts screens
• Remove antd-related global styles
• Add global link style as antd was impacting those

Test Plan:
npm test

This diff is live at https://cashtab-local-dev.netlify.app/

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D15939