Stable release plan for OtlpLogExporter

[vishweshbankwar]

Proposal

1. Resolve 4388 by adding a new extension method:

   public static LoggerProviderBuilder AddOtlpExporter(
   this LoggerProviderBuilder loggerProviderBuilder,
   Action<OtlpExporterOptions, LogRecordExportProcessorOptions> configureExporterOptions);

   In addition to this we will have following extension methods as well for users who would like to use the default settings.

   public static LoggerProviderBuilder AddOtlpExporter(this LoggerProviderBuilder builder);
   
   public static LoggerProviderBuilder AddOtlpExporter(this LoggerProviderBuilder builder, Action<OtlpExporterOptions> configureExporter);

   New class

   public class LogRecordExportProcessorOptions
   {
      public ExportProcessorType ExportProcessorType { get; set; }
      public BatchExportLogRecordProcessorOptions BatchExportProcessorOptions { get; set; }
   }

2. In favor of moving towards a consistent experience between logs and traces we will add the following extension method for traces:

    public static TracerProviderBuilder AddOtlpExporter(
    	this TracerProviderBuilder builder, 
    	Action<OtlpExporterOptions, ActivityExportProcessorOptions> configureExporterOptions)

   New class

   public class ActivityExportProcessorOptions
   {
      public ExportProcessorType ExportProcessorType { get; set; }
      public BatchExportActivityProcessorOptions BatchExportProcessorOptions { get; set; }
   }

3. Merge OpenTelemetry.Exporter.OpenTelemetryProtocol.Logs package in to OpenTelemetry.Exporter.OpenTelemetryProtocol.

4. Finalize dotnet.ilogger.category, logRecord.EventId.Id and logRecord.EventId.Name attribute names.

Post stable release
By following the plan above we would be able to release stable OtlpLogExporter. However, we will still have a feature gap of supporting signal specific environment variables i.e. OTEL_EXPORTER_OTLP_SIGNAL_*. Supporting this may require adding signal specific option classes. We will explore the design for this at later time.

[vishweshbankwar]

reference PR #4416

[vishweshbankwar]

Closing this one. An alternate approach was followed in #4733