Refactor temporality to align with the spec

[reyang]

Related to open-telemetry/opentelemetry-specification#2154.

Changes

Please provide a brief description of the changes here.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Design discussion issue #
• Changes in public API reviewed

[cijothomas]

changelog too.

[codecov]

Codecov Report

Merging #2666 (06cd90f) into main (8d339bb) will decrease coverage by 0.01%.
The diff coverage is 85.71%.

@@            Coverage Diff             @@
##             main    #2666      +/-   ##
==========================================
- Coverage   82.29%   82.27%   -0.02%     
==========================================
  Files         249      249              
  Lines        8703     8689      -14     
==========================================
- Hits         7162     7149      -13     
+ Misses       1541     1540       -1     

Impacted Files	Coverage Δ
...porter.OpenTelemetryProtocol/OtlpMetricExporter.cs	0.00% <ø> (ø)
...nTelemetryProtocol/OtlpMetricExporterExtensions.cs	0.00% <0.00%> (ø)
src/OpenTelemetry/Metrics/MetricReader.cs	87.87% <85.71%> (+0.04%)	⬆️
...lemetry/Metrics/AggregationTemporalityAttribute.cs	100.00% <100.00%> (ø)
...OpenTelemetry/Metrics/BaseExportingMetricReader.cs	89.09% <100.00%> (-0.20%)	⬇️
src/OpenTelemetry/Metrics/MetricReaderExt.cs	90.32% <100.00%> (-0.11%)	⬇️