refactor(sdk): delete code through refactor

[ByteBaker]

Closes #4573

• Keep transport selection in one place to simplify SDK maintenance.
• Replace 55 repeated matches with a private client accessor.

Rationale

There were lots of repeated client matches doing the same thing.

What changed?

• Replaced repeated lines with a new method ClientWrapper::as_client(...) -> &dyn Client which handles the enum branch-matching within itself.
• Add a test nested_client_wrapper_forwards_results_and_errors to test the SDK over various transport types.

GOOD: >650 net lines deleted.

Local Execution

• Passed
• Pre-commit hooks ran

AI Usage

1. Which tools? Codex
2. generated functions, mostly as a typist
3. Through tests and then manually read throught the whole thing
4. Absolutely.

[github-actions]

This PR is closed because its description has no Closes #N, Fixes #N, Resolves #N or Relates to #N line naming an issue.

Every PR needs an issue that was assigned to you before work started. See CONTRIBUTING.md.

[hubcio]

Please create an issue and reopen :)

[ByteBaker]

Hey @hubcio, I can't seem to reopen the issue. Seems like a permission thing. Could you please reopen this. Thanks 🙏

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.42%. Comparing base (fe3b426) to head (2e550b0).
⚠️ Report is 1 commits behind head on master.

❌ Your patch check has failed because the patch coverage (0.00%) is below the target coverage (50.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@              Coverage Diff              @@
##             master    #4571       +/-   ##
=============================================
- Coverage     89.49%   79.42%   -10.08%     
  Complexity     1784     1784               
=============================================
  Files          1330     1278       -52     
  Lines        284420   199500    -84920     
  Branches     242863   157945    -84918     
=============================================
- Hits         254551   158459    -96092     
- Misses        24227    35259    +11032     
- Partials       5642     5782      +140     

Components	Coverage Δ
Rust Core	79.30% <100.00%> (-11.45%)	⬇️
Java SDK	70.71% <ø> (ø)
C# SDK	66.08% <ø> (-13.30%)	⬇️
Python SDK	90.43% <ø> (ø)
PHP SDK	85.84% <ø> (ø)
Node SDK	95.12% <ø> (ø)
Go SDK	70.88% <ø> (ø)
C++ SDK	84.44% <ø> (ø)

Files with missing lines	Coverage Δ
core/sdk/src/client_wrappers/binary_client.rs	70.00% <ø> (ø)
...e/sdk/src/client_wrappers/binary_cluster_client.rs	100.00% <ø> (ø)
...rc/client_wrappers/binary_consumer_group_client.rs	85.71% <ø> (ø)
...c/client_wrappers/binary_consumer_offset_client.rs	100.00% <ø> (ø)
...e/sdk/src/client_wrappers/binary_message_client.rs	66.66% <ø> (ø)
...sdk/src/client_wrappers/binary_partition_client.rs	100.00% <ø> (ø)
...nt_wrappers/binary_personal_access_token_client.rs	100.00% <ø> (ø)
...e/sdk/src/client_wrappers/binary_segment_client.rs	100.00% <ø> (ø)
...re/sdk/src/client_wrappers/binary_stream_client.rs	100.00% <ø> (ø)
...re/sdk/src/client_wrappers/binary_system_client.rs	100.00% <ø> (ø)
... and 3 more

... and 450 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[haubur]

Hi @ByteBaker I like the refactor!
The pipeline failed for unrelated reasons which were fixed in the meantime.
A rebase should make it green.

[ByteBaker]

@haubur thank you! I like deleting code. I'll try more such work in the future, and occasionally feature/fixes as well where I understand the code better.