[SDK] Fix MetricProducer interface

[yashykt]

Fixes #3412

Changes

Cleans up the MetricProducer interface by removing the unused metric_filter_ parameter.

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[yashykt]

@IcySteam

[netlify]

✅ Deploy Preview for opentelemetry-cpp-api-docs canceled.

Name	Link
🔨 Latest commit	e0f2731
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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.06%. Comparing base (2faa400) to head (e0f2731).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3413      +/-   ##
==========================================
- Coverage   90.06%   90.06%   -0.00%     
==========================================
  Files         212      212              
  Lines        6939     6937       -2     
==========================================
- Hits         6249     6247       -2     
  Misses        690      690              

Files with missing lines	Coverage Δ
...opentelemetry/sdk/metrics/export/metric_producer.h	100.00% <100.00%> (ø)
sdk/src/metrics/state/metric_collector.cc	93.23% <100.00%> (ø)

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[IcySteam]

Thanks for the PR Yash, having two instances of metric_filter_ indeed looks to be an oversight.

Should we remove the metric_filter_ member from MetricCollector instead, in order to closer to match the description of the specs?

[yashykt]

Should we remove the metric_filter_ member from MetricCollector instead, in order to closer to match the description of the open-telemetry/opentelemetry-specification#3566?

I was not involved in the creation of the spec, but I don't think they intended to add member variables to interfaces (since that no longer would be a pure interface) . I think they just meant that child classes of MetricCollector should take in metric_filter_. Either that or as a parameter to Produce