Function zip 

pub fn zip(
    if_true: &dyn Array,
    if_false: &dyn Array,
    mask: &Mask,
) -> VortexResult<ArrayRef>

Performs element-wise conditional selection between two arrays based on a mask.

Returns a new array where result[i] = if_true[i] when mask[i] is true, otherwise result[i] = if_false[i].