Improved logging defaults and steam API error handling.

[Bash-09]

Mainly just some housekeeping:

• Improve logging defaults so there's no hyper spam in either the live log or the file
  • Even when manually overriding the log level to debug
• Replace usage of anyhow in steamapi.rs with thiserror for improved handling
  • Slight adjustment so if requesting one user fails, the rest can still succeed

I actually hope to remove anyhow altogether at some point, but I'll leave that for later so as not to interfere with Lilith's current MR.