Add support for some _download endpoints + typo fix

[trolldbois]

Description

add methods for several CSV report download endpoints

• containers
• defenders
• registry
• scans

and fix a typo in _stats.py

Motivation and Context

The module is missing methods for these API endpoints.

How Has This Been Tested?

Tested in production v32

Types of changes

• New feature
• bugfix

Checklist

• [ ] I have updated the documentation accordingly.
• [X] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes if appropriate.
• [ ] All new and existing tests passed.