Add handling of nested data structures to `obfuscator`

[CJohnston079]

Issue

Currently, the obfuscator handles shallow data, but has limited support for files such as .json and .xml that could potentially have nested data structures.

In order to fully support these file types and their potential for storing data, the obfuscator should be able to handle deep data.

Proposed resolution

• handle_json should already be able to process in its current implementation deep data using Python's built-in JSON library.
• handle_xml will need to be revised to traverse deep xml documents.
• obfuscate_fields will should recursively call itself if it encounters a list or dictionary element as a property.
• List-based (json) and dictionary based (xml) data structures will both need to be handled.

[CJohnston079]

Support for deep data is functional from 82754659db6e0f9c44bb169a8b49c454c3901b8c