Implement cardinality limits for metric streams

[lzchen]

Part of #1065

This PR implements a fixed cardinality limit for metric data points of the same stream to 2000. If an attempt to use an instrument to create a new metric data point for the same stream is made which would exceed the limit, the data point is added/recorded to the data point representing the overflow metric stream which is denoted by an AttributeSet containing only {otel.metric.overflow: True}.

Note there is a bit of duplication of code done on purpose to optimize for the most common scenarios, which is usually when an entry exists already within a hashmap.

[codecov]

Codecov Report

Patch coverage: 35.5% and project coverage change: -0.1 ⚠️

Comparison is base (e9adef6) 50.9% compared to head (6339e41) 50.8%.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1066     +/-   ##
=======================================
- Coverage   50.9%   50.8%   -0.1%     
=======================================
  Files        165     165             
  Lines      19689   19751     +62     
=======================================
+ Hits       10025   10037     +12     
- Misses      9664    9714     +50     

Impacted Files	Coverage Δ
...entelemetry-sdk/src/metrics/internal/last_value.rs	0.0% <0.0%> (ø)
opentelemetry-sdk/src/metrics/internal/sum.rs	21.0% <26.3%> (-0.3%)	⬇️
...entelemetry-sdk/src/metrics/internal/aggregator.rs	30.0% <42.8%> (+30.0%)	⬆️
...pentelemetry-sdk/src/metrics/internal/histogram.rs	60.1% <63.3%> (-2.9%)	⬇️

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