Support for specifying resouce attributes in Geneva traces exporter

[mattsains]

Fixes #2999

Changes

Copies resource attributes to exported spans in part C of common schema, and also maps the following resource attributes:

• service.name -> Geneva cloud.role
• service.instanceId -> Geneva cloud.roleInstance

I also made substantial changes to the unit test to make sure all spans generated in the tests are verified correctly.

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)

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: mattsains / name: Matthew Sainsbury (54e49e1, 63d136c)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 70.54%. Comparing base (2ee3971) to head (63d136c).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3214      +/-   ##
==========================================
- Coverage   70.63%   70.54%   -0.09%     
==========================================
  Files         440      430      -10     
  Lines       17213    17191      -22     
==========================================
- Hits        12159    12128      -31     
- Misses       5054     5063       +9     

Flag	Coverage Δ
unittests-Exporter.Geneva	53.94% <100.00%> (+0.60%)	⬆️
unittests-Instrumentation.Cassandra	?

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

Files with missing lines	Coverage Δ
...Telemetry.Exporter.Geneva/GenevaExporterOptions.cs	90.24% <ø> (ø)
...enTelemetry.Exporter.Geneva/GenevaTraceExporter.cs	82.50% <100.00%> (+0.44%)	⬆️
...xporter.Geneva/Internal/ConnectionStringBuilder.cs	93.00% <100.00%> (+0.14%)	⬆️
...xporter.Geneva/Internal/MsgPack/MsgPackExporter.cs	100.00% <100.00%> (ø)
...er.Geneva/Internal/MsgPack/MsgPackTraceExporter.cs	94.13% <100.00%> (+0.48%)	⬆️

... and 24 files with indirect coverage changes

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.