Multiple llm settings with own model and system prompt

[ninadkochkar]

Hi,
I'd like to propose a feature that would enable us to create multiple copies of LLM settings, each with a unique name. This would give us the flexibility to configure different models (like GPT-4 and GPT-4-mini) with their own specific system prompts. By doing so, we could easily switch between these models as needed.

[Taewan-P]

This would be a similar request: #58, #95