feat: add common data structures (BinarySection, BinaryString, InternalRow)

[lxy-9602]

Purpose

No Linked issue.

Introduce

• BinarySection — base class for binary data backed by a MemorySegment, providing offset/size-based access (binary_section.h/cpp)
• BinaryString — variable-length binary string with comparison, copy, hash, and substring operations (binary_string.h/cpp)
• DataDefine — variant type definitions (NullableDataField, DataField) for Paimon columnar data (data_define.h)
• DataGetters / DataSetters — abstract interfaces for typed columnar read/write access (data_getters.h, data_setters.h)
• InternalRow — abstract row interface with typed field accessors and field count (internal_row.h/cpp)
• InternalArray — abstract array interface for columnar array data (internal_array.h)
• InternalMap — abstract map interface wrapping key/value InternalArrays (internal_map.h)

Tests

• binary_section_test.cpp — BinarySection construction and memory access
• binary_string_test.cpp — BinaryString comparison, copy, hash, substring operations
• internal_row_test.cpp — InternalRow field access and JoinedRow correctness

API and Format

Documentation

Generative AI tooling

[leaves12138]

Thanks for the contribution. I found one blocker that should be fixed before merge.

BinarySection::HIGHEST_FIRST_BIT is defined as 0x80L << 56. In C++, this left-shifts a signed integer into the sign bit, which is undefined behavior when the result is not representable as a signed long. This mask is used by ReadBinary to distinguish inline fixed-length data from variable-length data, so compiler-dependent behavior here can break binary/string decoding.

Please define these masks using unsigned arithmetic and cast after the shift, for example static_cast<int64_t>(0x80ULL << 56) (and preferably use unsigned masks consistently for the related 0x7F mask as well).

[leaves12138]

Thanks for the update. The previous signed-shift issue is fixed, and I did not find any remaining blocking issue in this round.