feat: ide-assists, Unwrap array

[A4-Tacks]

Like Unwrap tuple

fn main() {
    $0let [foo, bar] = ["Foo", "Bar"];
}

->

fn main() {
    let foo = "Foo";
    let bar = "Bar";
}

[ChayimFriedman2]

I don't know if we should have this, because in my experience arrays (unlike tuples) are rarely used just to assign values to two (or more) variables. That is, when you destructure an array, you have an array and not building it in the same expression. Also, if we decide we want this, this likely needs code deduplication from "unwrap tuple".

[A4-Tacks]

Using an array can obtain consistent types, making type inference more convenient.