[geneva] Vendor code for writing tracepoints on Linux

[CodeBlanch]

[Split off from #2113]

Changes

• Adds code from https://github.com/microsoft/LinuxTracepoints-Net/ into the "External" folder in the GenevaExporter project. Decided to vendor this code because a) that package doesn't have a strong name which breaks the build and b) we're hoping dotnet/runtime will add support for user_events in the future and we won't need a dependency.

  Geneva will only be using the PerfTracepoint class. The files being included here are the subset from the repo required to get /Provider/PerfTracepoint.cs building.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 340 lines in your changes missing coverage. Please review.

Project coverage is 58.94%. Comparing base (71655ce) to head (cbd1ff9).
Report is 456 commits behind head on main.

Files with missing lines	Patch %	Lines
.../LinuxTracepoints-Net/Provider/TracepointHandle.cs	0.00%	178 Missing ⚠️
...al/LinuxTracepoints-Net/Provider/PerfTracepoint.cs	0.00%	87 Missing ⚠️
...nal/LinuxTracepoints-Net/Provider/RawFileHandle.cs	0.00%	35 Missing ⚠️
...xTracepoints-Net/Types/EventHeaderFieldEncoding.cs	0.00%	13 Missing ⚠️
.../External/LinuxTracepoints-Net/Provider/Utility.cs	0.00%	11 Missing ⚠️
...External/LinuxTracepoints-Net/Types/EventHeader.cs	0.00%	9 Missing ⚠️
...ernal/LinuxTracepoints-Net/Provider/DataSegment.cs	0.00%	3 Missing ⚠️
...xTracepoints-Net/Types/EventHeaderExtensionKind.cs	0.00%	2 Missing ⚠️
...nuxTracepoints-Net/Types/EventHeaderFieldFormat.cs	0.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2114       +/-   ##
===========================================
- Coverage   73.91%   58.94%   -14.98%     
===========================================
  Files         267       44      -223     
  Lines        9615     3924     -5691     
===========================================
- Hits         7107     2313     -4794     
+ Misses       2508     1611      -897     

Flag	Coverage Δ
unittests-Exporter.Geneva	58.94% <0.00%> (?)

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

Files with missing lines	Coverage Δ
...ry.Exporter.Geneva/External/TraceLoggingDynamic.cs	22.46% <ø> (ø)
...xTracepoints-Net/Types/EventHeaderExtensionKind.cs	0.00% <0.00%> (ø)
...nuxTracepoints-Net/Types/EventHeaderFieldFormat.cs	0.00% <0.00%> (ø)
...ernal/LinuxTracepoints-Net/Provider/DataSegment.cs	0.00% <0.00%> (ø)
...External/LinuxTracepoints-Net/Types/EventHeader.cs	0.00% <0.00%> (ø)
.../External/LinuxTracepoints-Net/Provider/Utility.cs	0.00% <0.00%> (ø)
...xTracepoints-Net/Types/EventHeaderFieldEncoding.cs	0.00% <0.00%> (ø)
...nal/LinuxTracepoints-Net/Provider/RawFileHandle.cs	0.00% <0.00%> (ø)
...al/LinuxTracepoints-Net/Provider/PerfTracepoint.cs	0.00% <0.00%> (ø)
.../LinuxTracepoints-Net/Provider/TracepointHandle.cs	0.00% <0.00%> (ø)

... and 250 files with indirect coverage changes

[rajkumar-rangaraj]

Could you please update the PR summary to show how you decided to select only part of these files from the other repo. Later if we need to copy an update it will be useful.

[rajkumar-rangaraj]

Also, consider adding information on why #nullable enable is added on every file.

[CodeBlanch]

@rajkumar-rangaraj @TimothyMothra I pushed some changes geared towards reducing the amount of changes to the files which are being vendored. Goal being to make it easier to update them in the future if needed.