[Otlp] Add persistent storage transmission handler

[vishweshbankwar]

Towards #4791
Design discussion issue #

Changes

Adds persistent storage handler for storing telemetry on disk. The handler will retry transmitting telemetry stored on disk at regular interval.

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 11 lines in your changes are missing coverage. Please review.

Project coverage is 85.53%. Comparing base (6250307) to head (40204ab).
Report is 146 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5460      +/-   ##
==========================================
+ Coverage   83.38%   85.53%   +2.14%     
==========================================
  Files         297      290       -7     
  Lines       12531    12606      +75     
==========================================
+ Hits        10449    10782     +333     
+ Misses       2082     1824     -258     

Flag	Coverage Δ
unittests	?
unittests-Solution-Experimental	85.47% <85.71%> (?)
unittests-Solution-Stable	85.50% <85.71%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...tation/OpenTelemetryProtocolExporterEventSource.cs	91.66% <100.00%> (-8.34%)	⬇️
...on/Transmission/OtlpExporterTransmissionHandler.cs	94.11% <100.00%> (ø)
...tlpExporterPersistentStorageTransmissionHandler.cs	83.82% <83.82%> (ø)

... and 64 files with indirect coverage changes

[CodeBlanch]

LGTM

[utpilla]

Not for this PR but it would be nice to also log the telemetry signal that was being sent. We should do it for other methods in this class too.