Add HTTP/Protobuf exporter for OTLP Logs

[cijothomas]

Covering one more gap in OTLP Logs!
Towards #2482

[CodeBlanch]

LGTM

[codecov]

Codecov Report

Merging #3225 (bb45fcb) into main (06d623b) will decrease coverage by 0.12%.
The diff coverage is 36.00%.

@@            Coverage Diff             @@
##             main    #3225      +/-   ##
==========================================
- Coverage   85.72%   85.60%   -0.13%     
==========================================
  Files         260      261       +1     
  Lines        9366     9390      +24     
==========================================
+ Hits         8029     8038       +9     
- Misses       1337     1352      +15     

Impacted Files	Coverage Δ
...ementation/ExportClient/OtlpGrpcLogExportClient.cs	78.57% <ø> (ø)
...ementation/ExportClient/OtlpHttpLogExportClient.cs	0.00% <0.00%> (ø)
...TelemetryProtocol/OtlpExporterOptionsExtensions.cs	97.87% <100.00%> (+0.19%)	⬆️
....Exporter.OpenTelemetryProtocol/OtlpLogExporter.cs	70.00% <100.00%> (ø)
...tation/OpenTelemetryProtocolExporterEventSource.cs	85.00% <0.00%> (-15.00%)	⬇️
...porter.OpenTelemetryProtocol/OtlpMetricExporter.cs	72.72% <0.00%> (-13.64%)	⬇️
...metryProtocol/Implementation/ActivityExtensions.cs	92.34% <0.00%> (+0.90%)	⬆️
src/OpenTelemetry/BatchExportProcessor.cs	89.47% <0.00%> (+2.10%)	⬆️
...emetry.Api/Internal/OpenTelemetryApiEventSource.cs	79.41% <0.00%> (+5.88%)	⬆️
...ZPages/Implementation/ZPagesExporterEventSource.cs	62.50% <0.00%> (+6.25%)	⬆️