Cannot dynamically populate a drop down when it is part a dialog

### Current Behavior

_No response_

### Expected Behavior

Either permit the drop down to be populated before being shown in a dialogue group or update the UI control to emit an event upon showing and closing of a dialog.

### Steps To Reproduce

Create a dialog group and add a drop down widget
Use an inject to populate the dialog
Send a message to the UI control to open the dialog
Drop down is empty

My initial thoughts were to use UI control to populate the drop-down, but UI control does not emit an event upon opening of a dialog group

### Environment

- Dashboard version: 1.25
- Node-RED version:
- Node.js version:
- npm version:
- Platform/OS:
- Browser:

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate