Implement InstrumentationLibrary Instance in SDK

[lalitb]

As per specs for Tracer Creation :

New Tracer instances are always created through a TracerProvider (see API). The name and version arguments supplied to the TracerProvider must be used to create an InstrumentationLibrary instance which is stored on the created Tracer.

Currently for cpp, we do pass instrumentation library name and version in tracer sdk, but it is never used internally to create InstrumentationLibrary instance, and further passing it to otel (and other) exporters:

opentelemetry-cpp/sdk/include/opentelemetry/sdk/trace/tracer_provider.h

Lines 35 to 37 in 25a7178

	opentelemetry::nostd::shared_ptr<opentelemetry::trace::Tracer> GetTracer(
	nostd::string_view library_name,
	nostd::string_view library_version = "") noexcept override;

As per the otel protocol:
https://github.com/open-telemetry/opentelemetry-proto/blob/e73df7c9f3c474c992990e82aa09ee46c39d6aab/opentelemetry/proto/common/v1/common.proto#L72-L78:

// InstrumentationLibrary is a message representing the instrumentation library information
// such as the fully qualified name and version. 
message InstrumentationLibrary {
  // An empty instrumentation library name means the name is unknown. 
  string name = 1;
  string version = 2;
}

`

[ThomsonTan]

Do we need create a definition of InstrumentationLibrary for SDK or reuse the definition from OTLP? Reuse it will introduce dependency on protobuf.

[lalitb]

Do we need create a definition of InstrumentationLibrary for SDK or reuse the definition from OTLP? Reuse it will introduce dependency on protobuf.

Yes, we need to create SDK implementation ( without protobuf dependency), and then propagate to otlp exporter.