Add support for reading from a byte-container for cbor and ubjson

[Ian-Flury]

• Adds a ContiguousByteContainer concept.
• Adds support in the cbor and ubjson read functions for reading from a ContiguousByteContainer.
• I'm not sure whether it's better to leave the concepts more generic, or build them as wrappers around the jsoncons library's type traits, maybe in include/thirdparty/jsoncons_config.hpp.

[gemini-code-assist]

Summary of Changes

Hello @Ian-Flury, 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 enhances the flexibility of the rfl library's CBOR and UBJSON deserialization capabilities. By introducing C++20 concepts for byte containers, the read functions can now seamlessly process data from various contiguous byte sources, making the library more adaptable to different data storage patterns and potentially improving performance by avoiding unnecessary data conversions.

Highlights

• New C++20 Concepts: Introduced a new rfl/concepts.hpp header defining C++20 concepts such as ByteLike, ContiguousByteContainer, MutableContiguousByteContainer, BackInsertableByteContainer, and ByteSpanLike. These concepts provide a robust way to specify requirements for byte-oriented data structures.
• Generalized Read Functions: The read functions for CBOR and UBJSON deserialization have been updated to leverage the new ContiguousByteContainer concept. This change allows these functions to accept a wider variety of input types beyond std::vector<char>, such as std::array, std::string_view, and std::span, improving flexibility and reducing the need for data copies.
• Expanded Test Coverage: New test files (tests/cbor/test_read_byte_containers.cpp, tests/ubjson/test_read_byte_containers.cpp, tests/generic/test_byte_containers.cpp) have been added to validate the new byte container concepts and demonstrate the generalized read functionality with different container types like std::array<std::byte, ...> and std::basic_string_view<std::byte>.

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[gemini-code-assist]

Code Review

This pull request introduces a ContiguousByteContainer concept to allow cbor and ubjson read functions to work with a variety of byte containers, not just std::vector<char>. This enhances API flexibility. The changes include new concepts, updated function signatures, and tests. The feedback focuses on refining the C++ concepts for improved clarity.

[gemini-code-assist]

The MutableContiguousByteContainer concept extends ContiguousByteContainer and adds requirements for mutable access. However, the checks for std::output_iterator on c.begin() and c.end() might be redundant and semantically confusing, as one cannot typically write to an end iterator. Relying on the non-const data() method on line 42 might be a clearer way to ensure mutability.

[liuzicheng1987]

@Ian-Flury thanks for your contribution.