feat: license.licensing implementation

[lmco-shuynh]

Description

Adds license.licensing support. Adding this helps support our internal use cases for tracking vendor licensing terms for software we purchase/license.

Resolves or fixes issue: #578

AI Tool Disclosure

• My contribution does not include any AI-generated content
• My contribution includes AI-generated content, as disclosed below:
  • AI Tools: Windsurf
  • LLMs and versions: Claude Opus 4.6 Thinking
  • Prompts: Ex: Create unit tests to exercise the newly added licensing field in license. Update documentation to reflect newly added changes

Affirmation

• My code follows the CONTRIBUTING.md guidelines

[read-the-docs-community]

Documentation build overview

📚 CycloneDX Python Library | 🛠️ Build #31849049 | 📁 Comparing 0075126 against latest (3ccfa4f)

🔍 Preview build

Show files changed (3 files in total): 📝 3 modified | ➕ 0 added | ➖ 0 deleted

File	Status
genindex.html	📝 modified
schema-support.html	📝 modified
autoapi/cyclonedx/model/license/index.html	📝 modified

[jkowalleck]

thank you for taking care of this feature, @lmco-shuynh

please add the new capability to the existing test model in https://github.com/CycloneDX/cyclonedx-python-lib/blob/main/tests/_data/models.py
i think get_bom_with_licenses should be the right place , similar as #947 done it

[jkowalleck]

@lmco-shuynh please rebase onto latest main branch

[lmco-shuynh]

@jkowalleck I've rebased, updated some URLs, and updated the test for get_bom_with_licenses.

Thanks for your help reviewing these changes