[Scalabrese] Improved Ollama integration

[scalabreseGD]

1. Improved Ollama
   a. Added Ollama Python client
   b. Fixed function for SQL extraction
   c. Improved extraction in case of Mistral with squared bracket
   d. Improved extraction making it case insensitive
   e. Pulled the model in case is not existing
   f. Added parameters such as keep_alive, num_ctx and additional parameters to be passed to the ollama server
2. Added Ollama as extra dependency

[zainhoda]

Thanks @scalabreseGD ! This is looking pretty good. One thing I've been encountering is that if model is set to something like mistral, the model_lists contains mistral:latest, so it pulls the model on every call. Do you have any thoughts on the best way to handle that?

[scalabreseGD]

@zainhoda changed the codebase pulling it only at the startup. Is not necessary to check it every time :)