Function resolve_unsuffixed_unary_op_operand 

fn resolve_unsuffixed_unary_op_operand(
    val: &Value,
    op: &UnaryOperation,
    expected_ty: &Option<Type>,
    span: &Span,
) -> Result<Value>

Resolves an unsuffixed operand for a unary operation by inferring its type based on the operation and an optional expected type. Uses predefined types (Field or Group) for specific operations, otherwise defaults to the expected type if available. Returns the resolved Value or an error if type resolution fails.