Semconv OTLP stable HTTP metrics

[mmatur]

What does this PR do?

Add semconv otlp metrics

Only the two stable metrics are added:

• http.server.request.duration
• http.client.request.duration

Semantic convention document is available here

Motivation

Fixes: #10219

More

• Added/updated tests
• Added/updated documentation

Additional Notes

Co-authored-by: Romain rtribotte@users.noreply.github.com
Co-authored-by: Baptiste Mayelle baptiste.mayelle@traefik.io

[mmatur]

Adding no-merge, we still have a panic on Tracing integration tests, I still have to investigate beginning of next week.

[mloiseleur]

Mmmh 🤔, there is also a convention on GRPC metrics.
https://github.com/open-telemetry/semantic-conventions/blob/main/docs/rpc/grpc.md

I suggest to either precise this in PR title or cover the GRPC part.

[mmatur]

Mmmh 🤔, there is also a convention on GRPC metrics. https://github.com/open-telemetry/semantic-conventions/blob/main/docs/rpc/grpc.md

I suggest to either precise this in PR title or cover the GRPC part.

The gRPC semantic convention are still experimental, we are handling only stable metrics

[nmengin]

LGTM