Common Fine-tuning API in Genkit

[ManiDoraisamy]

Is your feature request related to a problem? Please describe.
Its not easy to switch between different AI vendors for fine-tuning purposes. So, I built "Genkit on top of Google Sheets" sometime back (promptrepo.com). But, I have implemented fine-tuning only for OpenAI. This limits my ability to leverage the strengths of various vendors in terms of accuracy and cost.

Describe the solution you'd like
I would like Genkit to support a common API for feeding data into a fine-tuning process across different vendors. Additionally, it should include a callback functionality to notify once the fine-tuning is completed. This would allow me to migrate my solution to Genkit and easily switch between vendors.

Describe alternatives you've considered
I have considered building separate fine-tuning implementations for each vendor, but this approach is time-consuming and lacks the efficiency and consistency of having a unified API within Genkit.

Additional context
Implementing this feature would significantly enhance the flexibility and utility of Genkit for users who, like me, need to work with multiple AI vendors. Here is a link to my current implementation for reference: promptrepo.com.