FramelessOffsetWindowFunctionFrame fails when ignore nulls and offset > # of rows

Failure when function that utilized `FramelessOffsetWindowFunctionFrame` is used with `ignoreNulls = true` and `offset > rowCount`.

e.g.

```
select x, lead(x, 5) IGNORE NULLS over (order by x) from (select explode(sequence(1, 3)) x)
```