[DataBinder] Avoid std::span/iter_move ambiguity on MSVC STL

[christianparpart]

Problem

SqlDynamicBinary exposes its byte payload as std::span<value_type const> (the constructor parameter, Bytes(), and the deprecated ToStringView()).

On Microsoft's STL, instantiating std::span<uint8_t const> realizes its std::reverse_iterator specialization, which declares the legacy std::iter_move hidden friend. Once that overload is visible in a translation unit, the unqualified iter_move call inside std::ranges::enumerate_view's iterator becomes ambiguous between it and the std::ranges::iter_move CPO. Any translation unit that both instantiates SqlDynamicBinary and uses std::views::enumerate then fails to compile:

error C2872: 'iter_move': ambiguous symbol

It reproduces with cl.exe under /O2 (force-inlining realizes the span iterator machinery). clang-cl, libstdc++ and libc++ are unaffected — it is a known MSVC STL interaction, not a defect in this library.

Fix

Introduce a ByteView alias and select the view type per standard library:

• std::basic_string_view<value_type> on MSVC's STL (_MSVC_STL_VERSION) — its iterators do not pull the conflicting iter_move into scope;
• std::span<value_type const> everywhere else.

std::span is retained off-MSVC because std::basic_string_view<uint8_t> is ill-formed there (no std::char_traits specialization for unsigned char), which is why the span form was adopted originally.

No public API changes beyond the view type alias; Bytes()/ToStringView() keep their contract.