Pattern match on variable/argument code action doesn't work on lists

[giacomocavalieri]

If I have this piece of code:

pub fn wibble(list: List(a)) {
  //          ^^^^
  todo
}

I'd like to trigger the pattern match on argument code action on list and get something like this:

pub fn wibble(list: List(a)) {
  case list {
    [first, ..rest] -> todo
    [] -> todo
  }
  todo
}