Fix dnscaa crash on unrecognized CAA properties

[liquidsec]

Summary

• Hickory-dns wraps unrecognized CAA property tags (e.g. contactemail, contactphone) as {"Unknown": "name"} instead of a plain string, causing 'dict' object has no attribute 'lower' in handle_event
• Unwrap the Unknown dict for both tag and value fields
• Extract emails from contactemail records (RFC 8657)
• Unknown properties with no handler are silently skipped

Closes #3191

[github-actions]

🚀 Performance Benchmark Report

⚠️ No current benchmark data available

This might be because:

• Benchmarks failed to run
• No benchmark tests found
• Dependencies missing

[codecov]

Codecov Report

❌ Patch coverage is 82.35294% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 90%. Comparing base (c07e3e7) to head (455178a).
⚠️ Report is 4 commits behind head on dev.

Files with missing lines	Patch %	Lines
bbot/modules/dnscaa.py	82%	3 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##             dev   #3193   +/-   ##
=====================================
- Coverage     90%     90%   -0%     
=====================================
  Files        449     449           
  Lines      44389   44405   +16     
=====================================
+ Hits       39716   39727   +11     
- Misses      4673    4678    +5     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.