Support all allowed SPDX output formats

## Short Description

Scancode Toolkit should support all allowed SPDX output formats.

## Possible Labels

- new feature
- sbom

## Select Category

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

## **Describe the Update**

At the moment, the default SPDX output options are limited to Tag/Value and RDF, while version 2.2.2 allows at least JSON, XML and YAML as well: https://spdx.github.io/spdx-spec/v2.2.2/conformance/#44-standard-data-format-requirements (It mentions Excel spreadsheets as well, but I do not really have a use case for it.)

## **How This Feature will help you/your organization**

SPDX uses a standardized file format supported by many application. I consider JSON and YAML more readable than Tag/Value or RDF.

## **Possible Solution/Implementation Details**

Add output support for JSON, XML and YAML.