feat(cpp): Add bazel building and testing infrastructure

[slbotbm]

Which issue does this PR close?

Closes #2762

Rationale

What changed?

Adds bazel build system + stub classes and their tests + ci scripts

Local Execution

• Passed
• Pre-commit hooks ran

AI Usage

If AI tools were used, please answer:

1. Which tools? codex
2. Scope of usage? build system implementation
3. How did you verify the generated code works correctly? checking on local environment
4. Can you explain every line of the code if asked? Yes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.98%. Comparing base (28e7c04) to head (0515a85).
⚠️ Report is 11 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #2785      +/-   ##
============================================
- Coverage     68.44%   67.98%   -0.47%     
- Complexity      656      708      +52     
============================================
  Files           852      873      +21     
  Lines         68196    69744    +1548     
  Branches      59657    60433     +776     
============================================
+ Hits          46679    47416     +737     
- Misses        19187    19975     +788     
- Partials       2330     2353      +23     

Flag	Coverage Δ
csharp	67.06% <ø> (-0.21%)	⬇️
java	54.02% <ø> (+1.82%)	⬆️
python	0.00% <ø> (?)
rust	69.69% <ø> (+0.07%)	⬆️

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see 65 files with indirect coverage changes

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[atharvalade]

Nice work on the infra setup. the CI integration and Bazel config are clean.

Two things to fix before merge though: the Expiry class in iggy.hpp has all its getters (expiry_type(), expiry_value(), value()) under private: unlike the other three classes, so it's completely opaque after construction (and the test can only SUCCEED() without asserting anything). Also, the genrule srcs hard-codes just src/lib.rs as soon as a second .rs file is added, Bazel won't detect changes to it and will serve stale cached builds. Swapping to glob(["src/**/*.rs"]) should fix that.

[slbotbm]

@atharvalade thanks for the review! those were some things that had been left over from when I was experimenting with the public interface. I've standardized all of the getter functions and corrected the bazel build file as well.

[hubcio]

not a fan of this. what if find returns 0 results?
also, find | xargs without -print0/-0 breaks on filenames with spaces

[slbotbm]

@hubcio Thanks for the review. I'll address the other two comments after thinking about the best approach