Generate New Client Metrics in otelhttp

[MrAlias]

The semconv.HTTPClient already produces the existing v1.20.0 client metrics (#6002). The following methods need to be updated to produce the new client HTTP metrics:

• MetricOptions
• RecordMetrics
• RecordResponseSize

These updates should ensure that when OTEL_SEMCONV_STABILITY_OPT_IN="http/dup" is set the produced telemetry is compliant with these semantic conventions:

• http.client.request.duration
  • Do not include the experimental attributes.
• http.client.request.body.size

Do not include:

• http.client.response.body.size
• http.client.open_connections
• http.client.connection.duration
• http.client.active_requests

These metrics are optional, and since the existing instrumentation does not provide an equivalent, do not add additional metrics (at this time).

[ayoisaiah]

@MrAlias I'd like to take this one

[akstron]

Hi @ayoisaiah , are you currently working on it? If not, I would like to work on it.