Specify other parameters for API chat completion

[marcominerva]

Chat completion API can use some parameters that allow to fine tuning the assistant:

• temperature
• top_p
• n
• max_tokens
• presence_penalty
• frequency_penalty
• logit_bias

We need to think about adding these parameters to ChatGptNet, giving the ability to either specify default values at registration, using ChatGptOptions, or when sending a message, with an overload to the AskAsync method that accepts a new class with this properties.