Add AnyBinary: one logical type for any binary encoding

[emilk]

The byte-string sibling of AnyList: a quiver-only logical type that accepts any of arrow's binary encodings and reads them uniformly as &[u8].

Logical type	Accepts	Element value
AnyBinary	Binary, LargeBinary, BinaryView, FixedSizeBinary (any size)	&[u8]

let column = Column::<AnyBinary>::try_from(array)?; // Binary / LargeBinary / BinaryView / FixedSizeBinary
assert_eq!(column.value(0), b"abc");

Details

• Backed by an enum AnyTypedBinary over the four arrow binary arrays; downcast dispatches on array.data_type() and reads every element as &[u8].
• FixedSizeBinary is included (mirroring AnyList including FixedSizeList): at the arrow level FixedSizeBinaryArray::value(i) already returns &[u8] (length N), so it fits the uniform &[u8] element type — only quiver's dedicated FixedSizeBinary<N> wrapper exposes &[u8; N].
• Parse-only: implements LogicalType (so try_from/reading/column[i] work) but not ConcreteType — no single arrow datatype, so no from_values/Default/schema. Build a concrete encoding such as Column<Binary>.
• Reads stay O(1)/zero-copy; nullability via Option<AnyBinary> (top-level) like any other column.

Verification

• cargo clippy --all-features --all-targets clean, cargo fmt --all applied
• cargo test --all-features green, incl. a new any_binary_columns test: all four encodings read uniformly, RefType indexing, non-binary rejected, null handling (Option<AnyBinary> + non-nullable rejection, including FixedSizeBinary)
• cargo doc --document-private-items -D warnings clean
• README: added to the supported-types table and the AnyList section

🤖 Generated with Claude Code