Widgets that default to "Hidden" don't save their state between application restarts

[simihartstein]

Describe the bug

When widgets are created with defaultState: WidgetState.Hidden, they will not save their state between the application reopening. The widget will always start hidden.

The state will be restored correctly after switching frontstages. Including opening a different iModel.

To Reproduce

1. Create a UIProvider that

• provides a widget with the default state to hidden.
• has some way to open the widget.

2. Open the widget
3. Restart the application and open an iModel

The widget will start hidden.

Expected Behavior

I expect the widget would be restored to its former visibility, like all the other default widget states.

Screenshots

No response

Desktop (please complete the applicable information)

Desktop app
AppUI: 4.17.6
iTwinUI: 3.16.0

Additional context

No response