completer: popup positioning is wrong for transformed editor

### Describe the bug

I have an editor that is css-transformed (scaling and translation). The editor is working well thanks to the `hasCssTransforms` config property. However the completer popup is completely mis-positionned:

### Expected Behavior

I would expect the popup to be positioned according to the transformed editor no matter its scaling/translation.

### Current Behavior

The popup is positioning according to absolute screen coordinates.

### Reproduction Steps

## index.html
```html

ACE in Action

#editor {
width: 1400px;
height: 1400px;
position: absolute;
transform: scale(0.4) translate(200px, 200px);
left: 0, top: 0;
}
.wrapper {
background-color: red;
width: 50000px;
height: 50000px;
position: relative;
}

var editor = ace.edit("editor", {
mode: "ace/mode/javascript",
theme: "ace/theme/merbivore",
fontSize: 20,
hasCssTransforms: true,
enableBasicAutocompletion: true,
enableLiveAutocompletion: true,
});
editor.setTheme("ace/theme/monokai");
editor.session.setMode("ace/mode/javascript");

```


### Possible Solution

_No response_

### Additional Information/Context

_No response_

### Ace Version / Browser / OS / Keyboard layout

1.36.5 / Chrome 131.0