The `Value::List` and `Value::Record` variants have been consolidated
into a single `Value::Tuple` variant. This new variant uses a
`TupleData` struct to store values and an optional `Rc<Vec<Keyword>>`
for keys, allowing it to represent both ordered lists/tuples and
key-value records.
This change simplifies the internal representation and improves
performance by allowing schema sharing for records. It also includes
updates to the compiler, runtime, and tests to reflect the new
structure.
Michael Schimmel