[Extensions] Adds BaggageLogRecordProcessor

[matt-hensley]

Fixes #2353

Changes

Adds BaggageLogRecordProcessor and relevant tests.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[MikeGoldsmith]

This looks really good, thanks for your contribution @matt-hensley 🎉

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.12%. Comparing base (71655ce) to head (1c70d6f).
Report is 654 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2354       +/-   ##
===========================================
+ Coverage   73.91%   91.12%   +17.20%     
===========================================
  Files         267       11      -256     
  Lines        9615      214     -9401     
===========================================
- Hits         7107      195     -6912     
+ Misses       2508       19     -2489     

Flag	Coverage Δ
unittests-Extensions	91.12% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...y.Extensions/Internal/BaggageLogRecordProcessor.cs	100.00% <100.00%> (ø)
...ons/Internal/OpenTelemetryExtensionsEventSource.cs	60.00% <100.00%> (+14.54%)	⬆️
....Extensions/Logs/OpenTelemetryLoggingExtensions.cs	100.00% <100.00%> (ø)
...etry.Extensions/TracerProviderBuilderExtensions.cs	94.44% <100.00%> (+27.77%)	⬆️

... and 263 files with indirect coverage changes

[cijothomas]

Left some small comments, but nothing blocker

[CodeBlanch]

LGTM