Use exceptions inside the writers

[liuzicheng1987]

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[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 introduces a fundamental change to the error handling paradigm within the serialization framework. By transitioning from noexcept functions and simple return codes to C++ exceptions, the system aims to provide a more explicit and robust mechanism for reporting and managing errors during data serialization. This refactoring impacts a wide array of serialization formats, ensuring consistent error propagation and enhancing resource management, particularly evident in the JSON and BSON implementations.

Highlights

• Error Handling Strategy: The primary change involves a significant shift in error handling across all serialization writers. Functions that previously used noexcept or returned error codes now throw std::runtime_error exceptions to signal failures.
• Noexcept Removal: The noexcept specifier has been removed from a large number of writer methods across various formats (Avro, BSON, Cap'n Proto, CBOR, Flexbuffers, JSON, MessagePack, TOML, UBJSON, XML, YAML) to allow for exception propagation.
• Exception Introduction: Specific error conditions in BSON, JSON, and MessagePack writer implementations now explicitly throw std::runtime_error when underlying library calls fail.
• Result Monad for Avro and MessagePack: For Avro and MessagePack, top-level write functions now return a Result monad to encapsulate potential errors, with non-noexcept overloads calling .value() to re-throw exceptions if an error occurred.
• Resource Management Improvements: The JSON writer (json::Writer) now uses std::shared_ptr to manage yyjson_mut_doc resources, ensuring proper cleanup.
• Generic Byte Container Concept: BSON and MessagePack readers and writers have been updated to utilize a new concepts::MutableContiguousByteContainer for more generic handling of byte sequence types.

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[gemini-code-assist]

Code Review

This pull request is a great step forward in improving the robustness of the library. It refactors the writer classes to use exceptions for error handling, which is a significant and positive change. This is achieved by removing noexcept specifiers and, more importantly, adding checks for return values from the underlying serialization libraries, throwing exceptions on failure. The introduction of RAII for resource management in bson and json writers using std::shared_ptr with custom deleters is an excellent improvement for resource safety. The generalization of byte containers using concepts is also a good enhancement. I have found one place where an error check was missed, but otherwise, the changes are solid.