[shared] Tag transformer improvements

[CodeBlanch]

Changes

• Removed the static coupling used to attach event source logging to the tag transformer class

• Added nullable annotations

• Removed TagAndValueTransformer. This was only used by OtlpExporter and added a whole bunch of unnecessary indirection

• Merge requirement checklist

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

[codecov]

Codecov Report

Attention: Patch coverage is 67.08861% with 26 lines in your changes are missing coverage. Please review.

Project coverage is 85.49%. Comparing base (6250307) to head (331eb1a).
Report is 141 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5455      +/-   ##
==========================================
+ Coverage   83.38%   85.49%   +2.10%     
==========================================
  Files         297      289       -8     
  Lines       12531    12509      -22     
==========================================
+ Hits        10449    10694     +245     
+ Misses       2082     1815     -267     

Flag	Coverage Δ
unittests	?
unittests-Instrumentation-Experimental	24.19% <ø> (?)
unittests-Instrumentation-Stable	24.22% <ø> (?)
unittests-Solution-Experimental	85.50% <67.08%> (?)
unittests-Solution-Stable	85.39% <67.08%> (?)

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

Files	Coverage Δ
...metryProtocol/Implementation/ActivityExtensions.cs	95.93% <100.00%> (ø)
...rotocol/Implementation/OtlpLogRecordTransformer.cs	95.45% <100.00%> (+1.99%)	⬆️
...metryProtocol/Implementation/ResourceExtensions.cs	100.00% <100.00%> (ø)
....Exporter.OpenTelemetryProtocol/OtlpLogExporter.cs	88.88% <ø> (ø)
...porter.OpenTelemetryProtocol/OtlpMetricExporter.cs	79.16% <ø> (-4.17%)	⬇️
...xporter.OpenTelemetryProtocol/OtlpTraceExporter.cs	88.46% <ø> (-2.72%)	⬇️
...rc/OpenTelemetry.Exporter.Zipkin/ZipkinExporter.cs	88.54% <ø> (+3.10%)	⬆️
...tryProtocol/Implementation/MetricItemExtensions.cs	91.58% <66.66%> (+9.57%)	⬆️
...er.Console/Implementation/ConsoleTagTransformer.cs	30.00% <60.00%> (ø)
.../OpenTelemetry.Exporter.Console/ConsoleExporter.cs	66.66% <25.00%> (-8.34%)	⬇️
... and 5 more

... and 58 files with indirect coverage changes

[CodeBlanch]

Update...

Ran into some strange behaviors with nint[] and nuint[] on .NET Framework.

On .NET/Core, this test always passes:

        Assert.False(((Array)new nint[0]) is long[]);
        Assert.False(((Array)new nint[0]) is int[]);
        Assert.False(((Array)new nuint[0]) is long[]);
        Assert.False(((Array)new nuint[0]) is int[]);

On .NET Framework, the test varies based on processor architecture:

        // On x64
        Assert.True(((Array)new nint[0]) is long[]);
        Assert.False(((Array)new nint[0]) is int[]);
        Assert.True(((Array)new nuint[0]) is long[]);
        Assert.False(((Array)new nuint[0]) is int[]);

        // On x86
        Assert.False(((Array)new nint[0]) is long[]);
        Assert.True(((Array)new nint[0]) is int[]);
        Assert.False(((Array)new nuint[0]) is long[]);
        Assert.True(((Array)new nuint[0]) is int[]);

This test is consistent across .NET Framework and .NET/Core:

        Assert.False(((object)(nint)1) is long);
        Assert.False(((object)(nint)1) is int);
        Assert.False(((object)(nuint)1) is long);
        Assert.False(((object)(nuint)1) is int);

Everything worked before sort of accidentally but this change started causing exceptions on .NET Framework.

@utpilla and I chatted offline and we decided to revert that new behavior just to make sure nothing breaks for 1.8.0 release: 331eb1a