## Problem
PGLB/Neonkeeper needs to separate the concerns of connecting to compute,
and authenticating to compute.
Additionally, the code within `connect_to_compute` is rather messy,
spending effort on recovering the authentication info after
wake_compute.
## Summary of changes
Split `ConnCfg` into `ConnectInfo` and `AuthInfo`. `wake_compute` only
returns `ConnectInfo` and `AuthInfo` is determined separately from the
`handshake`/`authenticate` process.
Additionally, `ConnectInfo::connect_raw` is in-charge or establishing
the TLS connection, and the `postgres_client::Config::connect_raw` is
configured to use `NoTls` which will force it to skip the TLS
negotiation. This should just work.