Fix inconsistent exception logging patterns and add guidance

[VamshikrishnaMonagari]

Category A : Remove redundant e.getMessage() where exception is already passed as the Throwable parameter:

• GrpcExporter.java
• HttpExporter.java
• JaegerRemoteSampler.java (also fix stale FINEST log to pass exception as Throwable instead of concatenating)

Category B : Pass exception as Throwable instead of stringifying via getMessage(), so logging frameworks can render full stack traces:

• AutoConfiguredOpenTelemetrySdkBuilder.java
• DeclarativeConfiguration.java
• TracerShim.java
• SdkDoubleHistogram.java
• SdkLongHistogram.java

Add best practice guidance to CONTRIBUTING.md recommending the use of dedicated logger overloads that accept a Throwable parameter.

Resolves #8228

[codecov]

Codecov Report

❌ Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 90.28%. Comparing base (3c0f6ff) to head (718b3c7).

Files with missing lines	Patch %	Lines
...incubator/fileconfig/DeclarativeConfiguration.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #8231   +/-   ##
=========================================
  Coverage     90.27%   90.28%           
+ Complexity     7695     7692    -3     
=========================================
  Files           850      850           
  Lines         23207    23201    -6     
  Branches       2356     2356           
=========================================
- Hits          20951    20946    -5     
+ Misses         1531     1528    -3     
- Partials        725      727    +2     

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[jack-berg]

Sorry for the delayed review. I've reworked the CONTRIBUTING.md and introduced a knowledge base at https://github.com/open-telemetry/opentelemetry-java/tree/main/docs/knowledge

Can you merge main and include a section about this guidance in https://github.com/open-telemetry/opentelemetry-java/blob/main/docs/knowledge/general-patterns.md? Thanks!

[VamshikrishnaMonagari]

Sorry for the delayed review. I've reworked the CONTRIBUTING.md and introduced a knowledge base at https://github.com/open-telemetry/opentelemetry-java/tree/main/docs/knowledge

Can you merge main and include a section about this guidance in https://github.com/open-telemetry/opentelemetry-java/blob/main/docs/knowledge/general-patterns.md? Thanks!

Thanks for the heads up, @jack-berg ! I've rebased on main and moved the logging guidance over to the Logging section in docs/knowledge/general-patterns.md. The CONTRIBUTING.md is left untouched now. Let me know if the placement looks good.

[jack-berg]

Thanks!