[sdk-logs] Implement LoggerProviderSdk

[CodeBlanch]

Relates to #4433

Changes

• Implement LoggerProviderSdk in SDK.

Merge requirement checklist

• CONTRIBUTING guidelines followed (nullable enabled, static analysis, etc.)

[codecov]

Codecov Report

Merging #4453 (8ef395a) into main (361750c) will decrease coverage by 0.64%.
The diff coverage is 6.86%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4453      +/-   ##
==========================================
- Coverage   84.11%   83.47%   -0.64%     
==========================================
  Files         312      312              
  Lines       12367    12469     +102     
==========================================
+ Hits        10402    10408       +6     
- Misses       1965     2061      +96     

Impacted Files	Coverage Δ
src/OpenTelemetry/Logs/LoggerProviderSdk.cs	0.00% <0.00%> (ø)
...nTelemetry/Internal/OpenTelemetrySdkEventSource.cs	80.20% <57.14%> (-1.82%)	⬇️
src/OpenTelemetry/BaseExportProcessor.cs	84.00% <100.00%> (+1.39%)	⬆️
src/OpenTelemetry/BaseProcessor.cs	96.77% <100.00%> (+0.10%)	⬆️

... and 3 files with indirect coverage changes

[utpilla]

We probably don't need this as this should cover it:

OpenTelemetrySdkEventSource.Log.LoggerProviderSdkEvent($"Processors added = \"{processorsAdded}\".");

[CodeBlanch]

This is here because AddProcessor can be called after the provider has been created! But agree, it is wonky. I just took a stab at cleaning it all up. Pushed a couple ToString implementations into public API. LMK what you think about it now!