Finish OpenAI integration for definition hint generation

[apmwebdev]

Description

This PR adds the UI components to the definition hints generated by the OpenAI API. It adds the hint field to the data sent to the front end, updates the TypeScript types, and changes the definition panel and obscurity panel to display the definition hints for words instead of the full definitions.

Related Issues

Resolves #113

Next Steps

The definition hints are unquestionably an improvement over the dictionary definitions for use in hint panels, but they are not perfect. Many hints still give away too much information, and some straight-up ignore the instructions, such as not to include any form of the root word in the hint. There will likely need to be iterative improvement on the hint generation logic before the hints are consistently generated correctly.

At a high level, this iterative improvement could include any of the following elements:

• UI functionality for marking words that have unacceptable hints and regenerating them (likely in batches)
• Using GPT 4 going forward and/or regenerating all existing hints using GPT 4 instead of GPT 3.5
• Refining the instructions for generating hints
• Fine-tuning an AI model for hint generation by giving it examples of good and bad hints