[Dev UI] JSON Prompt development data files for the genkit UI (prompt input data) -- for development and testing

[Tyg-g]

Is your feature request related to a problem? Please describe.

When testing a prompt or flow using the genkit UI, it would be handy to have there my testing data (prompt inputs) directly. It's frustrating to have to copy-paste it from different files on each occasion.

Describe the solution you'd like

So the genkit UI could also load files that contain input data for different prompts -- intended only for developing and testing the prompt.

These data coud be stored in files like:

• my-dev-data1.promptdata, or
• my-dev-data2.promptdata.json.

Describe alternatives you've considered

The only current alternative is copy-pasting.

Additional context

These files would make it easy for a dev to return to testing and development, providing a canonical way to store and load input data.

These files could be easily excluded from the production bundle based on their extension.

[Tyg-g]

This is a feature request, not sure how to tag it as such.