Create helper functions

[azaroth42]

Create an overlay API that adds helper functions to make it easier to perform common tasks, including:

• primary name
• alternate name
• vocabulary object/work types
• the main statement types
• production/creation details
• IIIF Manifest
• Web Page
• Digital Image
• Dimensions
• TimeSpan / Date Parsing
• Rights

This should assist both developers and AI code generators to be consistent in using linked art