Started implementation of temperature, top_k and logits for local models

[karemr2024]

• Removed hardcoded temperature, topk and logits
• Modified GeminiExecutor implementation to initialize temperature, topk and logits
• Modified atomic.rs config struct to include temperature, topk and logits
• Added the default values in case GeminiExecutor is initialized without new arguments
• Added test for new version of GeminiExecutor

[andthattoo]

Thanks for the contribution!

We can't merge this unless the newly added

    pub temperature: Option<f64>,   // Add temperature field
    pub top_k: Option<i32>,         // Add top_k field
    pub logits: Option<bool>, 

fields to Config struct are usable by each provider including OpenAI, Gemini, OpenRouter and Ollama.

Also logits are not supported by Ollama yet (see issue)

Only option is to work vLLM out for compute nodes so logits are supported. Maybe we can handle temp and top_k for all providers and keep them in the struct but remove logits until we have vLLM support.