[sdk-logs] Add LoggerProvider extensions

[CodeBlanch]

Relates to #4433

Changes

• Add extensions which allow users to invoke AddProcessor, Shutdown, & ForceFlush on a LoggerProvider instance.

Merge requirement checklist

• CONTRIBUTING guidelines followed (nullable enabled, static analysis, etc.)
• Unit tests added/updated

[codecov]

Codecov Report

Merging #4480 (a4a3301) into main (660d5b5) will increase coverage by 0.01%.
The diff coverage is 84.13%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4480      +/-   ##
==========================================
+ Coverage   85.13%   85.15%   +0.01%     
==========================================
  Files         314      315       +1     
  Lines       12524    12539      +15     
==========================================
+ Hits        10662    10677      +15     
  Misses       1862     1862              

Impacted Files	Coverage Δ
src/OpenTelemetry/Logs/LogRecord.cs	67.14% <66.41%> (ø)
src/OpenTelemetry/Logs/LogRecordScope.cs	82.60% <81.81%> (ø)
...lemetry/Logs/ILogger/OpenTelemetryLoggerOptions.cs	85.00% <84.21%> (ø)
src/OpenTelemetry/Logs/LoggerProviderExtensions.cs	86.66% <86.66%> (ø)
...penTelemetry/Logs/BatchLogRecordExportProcessor.cs	91.66% <90.90%> (ø)
src/OpenTelemetry/ProviderExtensions.cs	91.66% <91.66%> (ø)
...emetry/Logs/ILogger/OpenTelemetryLoggerProvider.cs	95.16% <94.73%> (ø)
...try/Logs/ILogger/OpenTelemetryLoggingExtensions.cs	100.00% <100.00%> (ø)
src/OpenTelemetry/Logs/LoggerProviderSdk.cs	92.78% <100.00%> (+3.09%)	⬆️
src/OpenTelemetry/Logs/Pool/LogRecordPoolHelper.cs	100.00% <100.00%> (ø)
... and 3 more

... and 4 files with indirect coverage changes