[Cashtab] Add 2 chronik nodes

Summary: Add 2 chronik nodes, these are 2 public nodes that support agora-plugin

Test Plan: npm test

Reviewers: bytesofman, O1 Bitcoin ABC, #bitcoin_abc

Reviewed By: bytesofman, O1 Bitcoin ABC, #bitcoin_abc

Subscribers: bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D17903