Filter from original rows, not current

#### What this does
Added option to filter from the original list of rows rather than what is currently being displayed

#### My reasoning
Just plugging this library into my app, I noticed the filter would only filter the rows that were displayed on screen, not the original set of rows loaded. I needed the ability to use backspace to start the filter over instead of hitting a reset button. If what I described is how this library actually works, then I may have been running into a bug and you can just close this PR.

#### Example
With this list:
```text
-- Luke
-- Jim
-- John
-- Johnny
```
Filtering to `Jo` would only show `John` and `Johnny`, but backspacing to just `J` wouldn't bring `Jim` back to the list.