Fix #2803, reduce complexity in cfe_sb_api.c

[Cameron-Sykes]

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name: FSW Code Change
about: Flight Software code changes
labels: fsw

Description of Change

Functions CFE_SB_CreatePipe() and CFE_SB_SubscribeFull() have high complexity. The complexity was lowered by ...

Linked Issue

Closes #2803

Requirements Impact

• Requirement ID(s): None
• Requirements updated as necessary
• Existing requirements are still satisfied by this change

Testing Evidence

• Link to complexity analysis CI run

Unit Tests (UT Assert)

• Link to CI run

COSMOS Test Suite

• Link to CI run

Areas of Expertise Touched

• ASTRO
• CI/CD
• COSMOS
• Cybersecurity
• Docker
• EDS
• Git
• PSPs
• SBN
• SMP
• Tables
• TSN
• Unit Tests
• Other

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Author Checklist

• Linked GitHub issue is referenced above
• Code has been formatted with .clang-format
• Static analysis workflows ran and passed
• Unit tests (UT Assert) updated/added to cover code changes
• Unit test workflows ran and passed
• COSMOS test suite was run; tests updated/added if relevant changes were made
• Requirements have been reviewed; updated or confirmed still satisfied (see above)
• Testing evidence is included above
• Self-review of the diff completed

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Reviewer Checklist

• Code logic is correct and matches the stated intent
• Code is readable, maintainable, and follows project conventions
• .clang-format has been applied
• Static analysis results reviewed and acceptable
• Unit tests are meaningful and adequately cover the changes
• The change has been exercised by the unit tests (not just that tests pass — the new/changed code paths are actually covered)
• COSMOS test suite was executed against this change and results reviewed (or confirmed N/A with justification)
• Reviewer has independently verified the change behaves as described (e.g., by running the tests locally, reviewing CI output in detail, or performing additional ad-hoc testing as warranted)
• Memory safety reviewed (allocation, bounds, lifetime, stack usage)
• Requirements impact reviewed and appropriate
• Error handling is appropriate
• Appropriate Expert areas have been reviewed

Reviewer Testing Notes

[sylvesterkaczmarek]

CFE_SB_MAX_PIPES_MET_EID is now emitted while CFE_SB_LockSharedData is held. EVS event delivery goes through CFE_SB_TransmitMsg, which acquires SB shared data again; the old PendingEventId path deliberately deferred these events until after the final unlock. Preserve that deferred-event pattern (or unlock before sending) and add a max-pipes regression that exercises event delivery.