Feature gap: MetricProducer

Is your feature request related to a problem?

We want to be able to easily read metrics from 3rd party metric sources

Describe the solution you'd like

The opentelemetry-cpp SDK contains a MetricProducer class which makes it very easy to work with 3rd party metric sources:

/**

• MetricProducer defines the interface which bridges to third-party metric sources MUST implement,
• so they can be plugged into an OpenTelemetry MetricReader as a source of aggregated metric data.
• Implementations must be thread-safe, and should accept configuration for the
• AggregationTemporality of produced metrics.
  */

https://github.com/open-telemetry/opentelemetry-cpp/blob/dbd06801eb767769a1ad427debfaf41ebb176cfa/sdk/include/opentelemetry/sdk/metrics/export/metric_producer.h#L75-L82

It'd be great if we can have this for Python as well.

Thank you!

Describe alternatives you've considered

No response

Additional Context

No response

Would you like to implement a fix?

None

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