[geneva] Rename metric transports

[CodeBlanch]

[Split off from #2113]

Changes

• Rename the metric transports in GenevaExporter to prepare for addition of MetricUnixUserEventsDataTransport

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 59.09%. Comparing base (71655ce) to head (51c68ae).
Report is 458 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2119       +/-   ##
===========================================
- Coverage   73.91%   59.09%   -14.82%     
===========================================
  Files         267       44      -223     
  Lines        9615     3924     -5691     
===========================================
- Hits         7107     2319     -4788     
+ Misses       2508     1605      -903     

Flag	Coverage Δ
unittests-Exporter.Geneva	59.09% <100.00%> (?)

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

Files with missing lines	Coverage Δ
...Metrics/OtlpProtobuf/OtlpProtobufMetricExporter.cs	69.23% <100.00%> (ø)
...metry.Exporter.Geneva/Metrics/TlvMetricExporter.cs	74.45% <100.00%> (ø)
...s/Transport/MetricUnixDomainSocketDataTransport.cs	85.71% <100.00%> (ø)
...ransport/MetricWindowsEventTracingDataTransport.cs	60.00% <100.00%> (ø)

... and 248 files with indirect coverage changes