Implement Ollama API client

[Ahmed-AmineHomman]

Add the wrapper/client for the Ollama API. In order to do this, one can use the ollama-python library.

• The app does NOT install/start the server (yet). The Ollama server thus should be running and available prior to the app start.
• The app uses the default localhost url (as if ollama & app runs on the same computer) by default, but allows to specify the base URL from an app parameter.
• The app also allows to choose the requested API from the start. Otherwise, it reads it from the config file.

[Ahmed-AmineHomman]

done in commit dd449d2e57ee837918130f2a9ea0fc76bf65496f