[sdk-metrics] ExemplarFilter updates to match latest specification#5404

CodeBlanch merged 8 commits intoopen-telemetry:mainopen-telemetry/opentelemetry-dotnet:mainfrom

CodeBlanch:sdk-metrics-exemplarfilter-spec-updatesCodeBlanch/opentelemetry-dotnet:sdk-metrics-exemplarfilter-spec-updatesCopy head branch name to clipboard