[repo] Add dedicated CI for Geneva Exporter

[CodeBlanch]

Changes

• Adds dedicated CI for OpenTelemetry.Exporter.Geneva

[codecov]

Codecov Report

Merging #1365 (3a2bec3) into main (71655ce) will increase coverage by 0.22%.
Report is 5 commits behind head on main.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1365      +/-   ##
==========================================
+ Coverage   73.91%   74.14%   +0.22%     
==========================================
  Files         267      258       -9     
  Lines        9615     9472     -143     
==========================================
- Hits         7107     7023      -84     
+ Misses       2508     2449      -59     

Flag	Coverage Δ
unittests	80.02% <100.00%> (?)
unittests-Exporter.Geneva	58.13% <ø> (?)
unittests-Exporter.OneCollector	89.71% <ø> (?)
unittests-Instrumentation.Process	100.00% <ø> (?)

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

Files Changed	Coverage
...ation.Owin/Implementation/DiagnosticsMiddleware.cs	100.00%
....Owin/Implementation/OwinInstrumentationMetrics.cs	100.00%
...inInstrumentationMeterProviderBuilderExtensions.cs	100.00%

[CodeBlanch]

Note: I don't have plans to do anymore of these but I wanted to do at least one on its own so we had a good example component authors (or whoever) could reference in order to repeat the process for other components.