[NEW] add failed login audit log

[coders-kitchen]

This PR adds the capability of logging failed login attempts. This can be used later for analysis / monitoring / fail2ban tooling.

The feature provides the option to

• be completely turned on / off
• select if one of the following information should be logged or not
  • Client IP
  • Forward For IP
  • UserAgent
  • Username

The log lines written are of this kind (in this example Forwarded For IP is enabled, everything else disabled)

Failed login detected - Username[unknown] ClientAddress[undefined] ForwardedFor[127.0.0.1] UserAgent[-]

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1 out of 2 committers have signed the CLA.

✅ coders-kitchen
❌ pdaum

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