Support Google Embedding through Google AI Studio instead of Vertex AI

[lpinilla]

Description

Google AI Studio offers a way to rapid test and prototype Gemini models without the need to configure a GCP project nor setup a billing account as Vertex AI requests.

Is this a bug or a feature?

• [ ] Bug
• [x] Feature

Steps to Reproduce

I would want to generate an API key on https://aistudio.google.com/app/apikey , set it up as an environment variable on the docker compose and be able to use Gemini embeddings and model.