Add support for parquet

[liuzicheng1987]

No description provided.

[gemini-code-assist]

Summary of Changes

Hello @liuzicheng1987, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly expands the data format capabilities of the reflect-cpp library by introducing robust support for Parquet. The changes enable users to seamlessly serialize and deserialize C++ data structures into the highly efficient columnar Parquet format, which is ideal for analytical workloads. The integration includes necessary build system updates, a comprehensive API for data manipulation, and detailed documentation outlining both the features and inherent limitations of working with tabular data.

Highlights

• New Feature: Parquet Support: This pull request introduces comprehensive support for the Parquet columnar storage format, enabling efficient serialization and deserialization of tabular data structures.
• Build System Integration: New CMake options (REFLECTCPP_PARQUET) have been added to enable Parquet support, along with integration with vcpkg to manage Apache Arrow and Parquet library dependencies.
• Core Parquet API: New C++ APIs (rfl::parquet::read, rfl::parquet::write, rfl::parquet::load, rfl::parquet::save) are provided for working with Parquet data, including options for compression and chunking.
• Documentation and Examples: Extensive documentation has been added in docs/supported_formats/parquet.md, detailing how to use Parquet with reflect-cpp, its specific limitations (e.g., handling of nested objects, variants, and arrays), and various use cases.
• Internal Reflection Improvements: The internal reflection mechanism has been updated to leverage C++20 concepts for has_reflection_method_v and has_reflection_type_v, and named_tuple_t now uses view_t for more flexible processing.
• Timestamp Handling Enhancement: The rfl::Timestamp class now includes a constructor from time_t and a to_time_t() method, which is crucial for accurate timestamp representation in Parquet.

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[gemini-code-assist]

Code Review

This pull request introduces support for the Parquet serialization format, a significant and welcome addition. The changes are extensive, touching the build system, adding a lot of new implementation files for Parquet, comprehensive tests, and documentation. The overall approach is consistent with the existing library design.

My review has identified a few issues:

• A critical copy-paste error in a new source file.
• Several issues in rfl::Timestamp related to thread-safety and correctness, which also affect the new Parquet implementation.
• An incorrect version for the Apache Arrow dependency in vcpkg.json and README.md that will prevent the project from building with vcpkg.
• A couple of minor issues, including a typo in the documentation and an opportunity to simplify a template with C++20 concepts.

After addressing these points, this will be a great contribution to the library.