Feature to record transitive dependecies in the generated SBOM

## Short Description

I tired running the tool on https://github.com/Inria/spoon with the following command:

```sh
scancode --json-pp sbom.json -clpeui .
```

It successfully output a JSON file. It had list of dependencies among many other things, but all the dependencies were direct. It would be nice to have a list of transitve dependencies as well. :)

## Possible Labels

- new feature

## Select Category

- [X] Enhancement
- [ ] Add License/Copyright
- [X] Scan Feature
- [ ] Packaging
- [ ] Documentation
- [ ] Expand Support
- [ ] Other

## **Describe the Update**

Ability to record transitive dependencies (or packages like the tool `-h` calls it).

## **Example/Links if Any**

[Maven Dependency Plugin](https://maven.apache.org/plugins/maven-dependency-plugin/tree-mojo.html) resolved transitive dependency.