GET v1/project does not return .children if onlyRoot=false

### Steps to Reproduce

1. Call v1/project
2. Observe `.children` attribute is missing from projects on the list
3. Call v1/project?onlyRoot=true
4. Observe `.children` attribute is present

### Expected Behavior

At least (non-recursive) children UUID is returned

### Dependency-Track Version

4.13.2

### Dependency-Track Distribution

Container Image

### Database Server

N/A

### Database Server Version

_No response_

### Browser

N/A

### Checklist

- [x] I have read and understand the [contributing guidelines](https://github.com/DependencyTrack/dependency-track/blob/master/CONTRIBUTING.md#filing-issues)
- [x] I have checked the [existing issues](https://github.com/DependencyTrack/dependency-track/issues) for whether this defect was already reported