Add OTLP/HTTP metric exporter (#2891)

Author: RangelReale

CHANGELOG.md

@@ -15,6 +15,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#2959](https://github.com/open-telemetry/opentelemetry-python/pull/2959))
 - Add http-metric instrument names to semantic conventions
   ([#2976](https://github.com/open-telemetry/opentelemetry-python/pull/2976))
+- [exporter/opentelemetry-exporter-otlp-proto-http] Add OTLPMetricExporter
+  ([#2891](https://github.com/open-telemetry/opentelemetry-python/pull/2891))
 
 ## [1.13.0-0.34b0](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.13.0) - 2022-09-26