Rename to Base2ExponentialBucketHistogram to align with the latest spec

[reyang]

Keep up open-telemetry/opentelemetry-specification#3041.
Only internal changes, no changelog entry.
I'll send another PR to cover open-telemetry/opentelemetry-specification#3017.

[codecov]

Codecov Report

Merging #4079 (bfbb1c6) into main (f98f8fe) will increase coverage by 0.04%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4079      +/-   ##
==========================================
+ Coverage   85.64%   85.68%   +0.04%     
==========================================
  Files         289      289              
  Lines       11255    11255              
==========================================
+ Hits         9639     9644       +5     
+ Misses       1616     1611       -5     

Impacted Files	Coverage Δ
...cs/Base2ExponentialBucketHistogramConfiguration.cs	0.00% <ø> (ø)
...lemetry/Metrics/Base2ExponentialBucketHistogram.cs	78.26% <100.00%> (ø)
...ZPages/Implementation/ZPagesExporterEventSource.cs	56.25% <0.00%> (-6.25%)	⬇️
...lementation/SqlClientInstrumentationEventSource.cs	70.83% <0.00%> (-4.17%)	⬇️
...ter.ZPages/Implementation/ZPagesActivityTracker.cs	97.14% <0.00%> (-2.86%)	⬇️
...Telemetry/Internal/SelfDiagnosticsEventListener.cs	96.87% <0.00%> (-0.79%)	⬇️
src/OpenTelemetry/BatchExportProcessor.cs	84.11% <0.00%> (+1.86%)	⬆️
...p/Implementation/HttpInstrumentationEventSource.cs	76.00% <0.00%> (+4.00%)	⬆️
...porter.OpenTelemetryProtocol/OtlpMetricExporter.cs	86.36% <0.00%> (+13.63%)	⬆️
...tation/OpenTelemetryProtocolExporterEventSource.cs	100.00% <0.00%> (+15.00%)	⬆️