[inmemory-exporter] Add extension on LoggerProviderBuilder

[CodeBlanch]

Relates to #4433

Changes

• Adds an extension for registering InMemoryExporter against a LoggerProviderBuilder instance

Merge requirement checklist

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

[codecov]

Codecov Report

Merging #4541 (3ce59d7) into main (e67d44e) will decrease coverage by 0.04%.
The diff coverage is 50.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4541      +/-   ##
==========================================
- Coverage   85.58%   85.54%   -0.04%     
==========================================
  Files         320      320              
  Lines       12610    12615       +5     
==========================================
  Hits        10792    10792              
- Misses       1818     1823       +5     

Impacted Files	Coverage Δ
...rter.InMemory/InMemoryExporterLoggingExtensions.cs	66.66% <50.00%> (-23.34%)	⬇️

... and 5 files with indirect coverage changes

[utpilla]

Update the PR title.