test(python): Add tests for python sdk

[slbotbm]

Which issue does this PR address?

Closes #3317
Relates to #

Rationale

The python sdk only had a few happy path tests. This PR adds extensive testing for the sdk. Also explicitly maps errors, replacing unwraps.

What changed?

• added extensive tests, divided into files. Division was done to separate concerns.
• removed all usage of unwrap in the the rust code.
• moved code of iterator.rs into consumer.rs. No need for an extra file for a small amount of code.

Local Execution

• Passed
• Pre-commit hooks

AI Usage

If AI tools were used, please answer:

1. Which tools? codex
2. Scope of usage? code generation, investigation
3. How did you verify the generated code works correctly? read through and reasoned about the code, executed on my machine
4. Can you explain every line of the code if asked? Yes

[github-actions]

Thanks for the PR. It is labeled S-waiting-on-review and queued for review.

Slash commands (own line, regular comment) move it around the queue:

• /ready - back to S-waiting-on-review after addressing feedback
• /author - flip to S-waiting-on-author while you finish changes
• /request-review @user-or-team - request a reviewer

See CONTRIBUTING.md for details.

[codecov]

Codecov Report

❌ Patch coverage is 87.30159% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.48%. Comparing base (d254604) to head (66a44c2).

Files with missing lines	Patch %	Lines
foreign/python/src/consumer.rs	84.61%	4 Missing ⚠️
foreign/python/src/identifier.rs	71.42%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #3432      +/-   ##
============================================
+ Coverage     74.43%   74.48%   +0.04%     
  Complexity      943      943              
============================================
  Files          1245     1244       -1     
  Lines        121293   121309      +16     
  Branches      97599    97599              
============================================
+ Hits          90285    90353      +68     
+ Misses        28054    28002      -52     
  Partials       2954     2954              

Components	Coverage Δ
Rust Core	75.56% <ø> (ø)
Java SDK	58.44% <ø> (ø)
C# SDK	69.92% <ø> (ø)
Python SDK	89.74% <87.30%> (+8.67%)	⬆️
PHP SDK	83.57% <ø> (ø)
Node SDK	91.35% <ø> (ø)
Go SDK	40.20% <ø> (ø)

Files with missing lines	Coverage Δ
foreign/python/src/client.rs	97.62% <100.00%> (+5.76%)	⬆️
foreign/python/src/lib.rs	100.00% <ø> (ø)
foreign/python/src/send_message.rs	96.96% <100.00%> (+0.67%)	⬆️
foreign/python/src/consumer.rs	80.58% <84.61%> (+19.16%)	⬆️
foreign/python/src/identifier.rs	77.77% <71.42%> (-2.23%)	⬇️

... and 1 file with indirect coverage changes

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