feat: add basic https support to memgpt server for development where https is needed

[cpacker]

Closes #1043

• Adds ability to start memgpt server in HTTPS mode
  • memgpt server --use-ssl
  • the server will then listen on https instead of http
• By default, it will create a self-signed cert using OpenSSL
  • NOTE: relies on subprocess, which is probably not great but should do for now
  • Can modify to use a package like cryptography down the line / if the subprocess + openssl combo doesn't work for devs
• Devs can also use memgpt server --use-ssl --ssl-cert path/to/ssl/certfile --ssl-key path/to/ssl/keyfile to pass a specific cert+key file combo

[sarahwooders]

lgtm!