Audit logging improvements

[LarsSven]

We want to make more use of the audit logging, but there were some things missing from the current audit logging for us.

• Authentication logs for people logging in were not included in the audit logs filter, so the audit logs themselves were quite barebone in terms of what they showed (Mostly people starting SSH sessions). This filter now also includes the logs for HTTP authentication.
• Warpgate never logged HTTP authentication failures. These are now also logged
• IPs are added to HTTP authentication
• Improved rich log handling for HTTP authentication logs to pretty up the log entries.
• Prevent duplicate successful-authentication audit entries by emitting the success event only once per accepted auth state.