feat: CMake integration for vortex-ffi & vortex-cpp

[0ax1]

Summary

Make the C and C++ CMake builds self-contained by having CMake build the Rust FFI archive through Cargo instead of requiring a separate cargo build and manually locating its output.

This adds source-tree CMake targets suitable for vendored downstream projects:

add_subdirectory(path/to/vortex vortex)

target_link_libraries(c_target PRIVATE Vortex::ffi_static)
target_link_libraries(cpp_target PRIVATE Vortex::cpp_static)

[0ax1]

This lays the foundation to integrate Vortex into other C++ projects such as cuDF.

[codspeed-hq]

Merging this PR will improve performance by 15.38%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 3 improved benchmarks
✅ 2196 untouched benchmarks
⏩ 206 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	WallTime	arrow_checked_add_u32_avx2[16384]	21.4 µs	17.6 µs	+21.31%
⚡	Simulation	allocate_drop_arrow[0]	456.9 ns	402.7 ns	+13.45%
⚡	Simulation	allocate_drop_bytes[0]	520.2 ns	466 ns	+11.62%

Tip

Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing ad/cmake-rust-integration (4f1a465) with develop (a997c3f)}

Footnotes

1. 206 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩