Add username/password authentication to NATS across stack

[emersonian]

Update docker compose, anything that touches NATS, to use configurable username/password authentication as defined by ENV variables.

[ReadyMouse]

Note to self: The NATS server does seem to be accepting authentications, but somehow the btc-checkers (and other services) aren't parsing things correctly to hand it over.

Test: Sucessful

docker run --network hosh_default -it natsio/nats-box:latest nats sub -s "nats://user:password@nats:4222" ">"

[ReadyMouse]

It appears I have zec, http, btc, and publisher all authenticating to nats with a password. Note: Currently the password is stored plain text in the .env file.