[cashtab] Support agora txs for ALP tokens

Summary:
Support listing ALP tokens on Agora

Note that buys and cancels work, as these functions are just using already-tested library methods that use AgoraOffer as an input param (so, adjust "automagically" for ALP vs SLP).

The only different tx type is the listing tx. We add and test a new helper function for creating these target outputs.

Agora list txs need special parsing vs SLP list txs. Add that too.

Test Plan:
npm test

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

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D17203