[alias-server] log API requester and hostname

Summary:
T2965

Fetch and log IP addresses and host names that hit the server

Test Plan: node index.js, navigate to localhost:5000/aliases, check logs. Note: you won't get a good IP address in local testing.

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D13346