Cohere Client

[Hk669]

Why are these changes needed?

To enhance the support of non-OpenAI models with AutoGen. The Command family of models includes Command, Command R, and Command R+. Together, they are the text-generation LLMs powering conversational agents, summarization, copywriting, and similar use cases.

• Pricing Implemented
• API Checks
• Create
• tool calls
• get_usage

Related issue number

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[marklysze]

Added Cohere documentation. We're missing Groq documentation, so we will add that to here as well.