Add support to use other LLM platforms

[StashaS]

Context:
Current implementation supports only GCP, which is not fair for other vendors. :)

Task:

1. Split the tooklit logic to actual toolkit and client to request LLM model provider.
2. Move clients LLM provider logic to separate packages.
3. Add support and instructions for the popular LLM platforms.

Result:
User should be able to configure and choose LLM platform.

[b0noI]

more I think about this more I think we need to stick to just one. as we have learned, making even one work reliably is super hard, there are many bugs related to one specific LLMs. So, instead of rebuilding something like CrewAI we can be MUCH better but only for one very specific LLM :) that this will be our market to target, users of Gemini who want to have better agents building framework

[StashaS]

To mitigate recent failures, we can probably implement a series of test cases, which would check that responses from a model suites for the toolkit and ratio of failures.
For the current project state it would test prompts and Gemini responses adequacy. For the potential future models integrations, it would be a prerequisite.

[b0noI]

I love this idea
we can have acceptance tests
where we will define set of prompts and what is considered good enough quality