feat: Added 'Compare Images with Gemini' Flow Action

[anveshmupparaju]

This PR introduces a new Flow Action named "Compare Images with Gemini", which allows users to compare two images stored in the sys_attachment table using the Gemini model.

The action supports an optional prompt to customize the comparison output.

Features

• Accepts two sys_attachment records as input
• Uses Gemini model (e.g., gemini-pro) for image analysis
• Optional prompt input for tailored comparison
• Returns a string-based analysis of image differences and similarities

Use Cases

• Visual regression testing
• UI/UX design comparisons
• Document or screenshot change tracking

Gemini Vision Docs

https://ai.google.dev/gemini-api/docs/image-understanding

How to get an API Key

• Visit https://aistudio.google.com/ to get an API key.
• Then create a credential of API key and then create Credential Alias

[github-actions]

✅ Valid PR for ActionPack

Thank you for your contribution. This PR complies with the CONTRIBUTING.md.
A maintainer will review this shortly. In the meantime, Happy Hacking!

[snamjosh]

Thank you for your contribution.