Uncollate an array of structs into arrays of fields.
```rs
pub struct Dog {
}
let dog1 = Dog { name: "Bandit", breed: "Beagle" };
let dog2 = Dog { name: "Scout", breed: "Pug"};
let dogs = vec![dog1, dog2]
//Vec<String> ["Bandit", "Scout"]
dogs.uncoll_name();
//Vec<String> ["Beagle", "Pug"]
dogs.uncoll_breed();
```