[Cashtab] Debounce wallet select

Summary:
T3566

Debounce the wallet select function

Ref https://www.carlrippon.com/using-lodash-debounce-with-react-and-ts/ on the implementation

Test Plan:
npm test

npm start or visit https://cashtab-local-dev.netlify.app/ and rapidly switch between wallets. Note the bug in the T3566 video is not repeated.

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D16123