Title and Icon are not resetting properly after browser refresh and null setting

### Current Behavior

Title and icon values are not resetting back to the default after setting the particular dynamic property values to null

### Expected Behavior

Widgets should display the original value after settings dynamic properties to null

### Steps To Reproduce

1. Add a text input or gauge node.
2. Set a title via widget properties.
3. Update title or icon dynamically using an inject node.
4. Reload the dashboard 2.0 after the particular value got updated in the UI.
5. set `null` to dynamic properties and inject.

### Environment

- Dashboard version: 1.15.0
- Node-RED version: 4.0.2
- Node.js version: 20
- npm version:
- Platform/OS:
- Browser:

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

I have provided an initial effort estimate