[ feature ] Simplify Azure Connection Handler

[LukeLalor]

I as a developer want to clearly differentiate between using a token provider and traditional auth when configuring Azure.

Similarly, I want a unique LLM provider so I do not need to dive into the depths of the openai configuration to figure out how to use Azure.

• [ ] Azure LLM Unit
• [ ] Clear Config for traditional auth vs token provider
• [ ] Configuration can be defined via documentation fields rather than magic envars

[LukeLalor]

See #741 for motivating conversation