[token-server, cashtab-faucet] Split token-server into two apps for faucet and token icon mgmt

Summary:
These apps do not belong together. They both happen to use API endpoints.

We should split these up. Have some improvements that should get in for both of these apps, but it would be convoluted to add them to this frankenstein combo server.

So first, split the apps without altering any functionality.

Test Plan:
npm test in each, will need some CI config work for cashtab-faucet ... will mb have to test in prod a bit with teamcity deployments but that's ok for this type of thing

docker build -f token-server.Dockerfile -t token-server_local .

docker build -f cashtab-faucet.Dockerfile -t cashtab-facuet_local .

tbh this will probably break stuff when it lands. I will back up the icons before landing. For these apps, if I need to do some troubleshooting to iterate back to their current prod state, that's acceptable. Both of the apps need lots of upgrades, and even taking 4 hrs of downtime to get them to an upgradeable state would be worth it.

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D18358