[BUG]: Multiline editing is broken in the REPL

### Description

After keybindings, some multiline editing features like continuous backspaces into the previous line and moving back to the previous line using left arrow, is broken. It's because we are intercepting these keys in the editor actions itself.

Also when the completer tab is on, backspace is acting twice, I believe for the same reason.

This will be fixed when we add the ability to configure existing actions (like the multiline actions itself), where we'll club the logic of backspaces, left arrows, and right arrows in one place.

### Related Issues

Related issues #2647 .

### Questions

No.

### Demo

_No response_

### Reproduction

- Try to hit backspace or left arrow when at the beginning of a line, in a multiline input.

### Expected Results

It should go back to the previous line.

### Actual Results

Doesn't go back to the previous line.

### Environments

Node.js

### Checklist

- [x] Read and understood the [Code of Conduct](https://github.com/stdlib-js/stdlib/blob/develop/CODE_OF_CONDUCT.md).
- [x] Searched for existing issues and pull requests.