Enhancement: Support for new cohere chat model family

[forestsource]

What features would you like to see added?

New models were Command-R + by cohereand I would love to see support for them in Librechat.
specification: https://docs.cohere.com/reference/chat

More details

For some reason unknown to us, cohere's requests use POST. This is unfortunate because the extension described in librechat.yaml only supports GET, resulting in an error.

LibreChat  | {
LibreChat  |   baseURL: "https://api.cohere.ai/v1",
LibreChat  |     modelOptions.model: "command-r-plus",
LibreChat  |     modelOptions.temperature: 1,
LibreChat  |     modelOptions.top_p: 1,
LibreChat  |     modelOptions.presence_penalty: 0,
LibreChat  |     modelOptions.frequency_penalty: 0,
LibreChat  |     // 3 stop(s)
LibreChat  |     modelOptions.stop: ["||>","\nUser:","<|diff_marker|>"],
LibreChat  |     modelOptions.user: "64b80765ede492ab9fccb5fc",
LibreChat  |     modelOptions.stream: true,
LibreChat  |     // 3 message(s)
LibreChat  |     modelOptions.messages: [{"role":"user","content":"test"},{"role":"assistant","content":"405 status code (no body)"},{"role":"user","content":"test"}],
LibreChat  | }
LibreChat  | 2024-04-05T06:11:45.007Z warn: [OpenAIClient.chatCompletion][stream] API error
LibreChat  | 2024-04-05T06:11:45.010Z error: [handleAbortError] AI response error; aborting request: 405 status code (no body)
LibreChat  | 2024-04-05T06:11:45.024Z debug: [AskController] Request closed

Thank you very much for all of your work!

Which components are impacted by your request?

No response

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[danny-avila]

from a quick glance, I don't think this is the issue

For some reason unknown to us, cohere's requests use POST. This is unfortunate because the extension described in librechat.yaml only supports GET, resulting in an error.

it is the different "chat" endpoint they are using

v1/chat instead of v1/chat/completions

I'll see if there is a quick fix for this for easy integration.