Adding external assistant with self set API-KEY HEADER

to add ChatGPT from Microsoft Azure OpenAI, we need to make the call with the Auth in Header with the key "api-key" instead "x-api-key".

Therefore, it would be good to have this option, where the wxo-admin can set the key of the API_KEY option.

See discussion: https://ibm-cloud.slack.com/archives/C05B099DNG6/p1739348078327359

here is the response of a curl call:

curl

curl -X POST "https://INSTANCE_ID.openai.azure.com/openai/deployments/DEPLOYMENT_MODEL/chat/completions?api-version=2024-02-15-preview" -H "Content-Type: application/json" -H "api-key: ABC" -d '{"messages":[{"role":"system","content":[{"type":"text","text":"You are an AI assistant that helps people find information."}]}],"temperature":0.7,"top_p":0.95,"max_tokens":800}'

{"choices":[{"content_filter_results":{"hate":{"filtered":false,"severity":"safe"},"protected_material_code":{"filtered":false,"detected":false},"protected_material_text":{"filtered":false,"detected":false},"self_harm":{"filtered":false,"severity":"safe"},"sexual":{"filtered":false,"severity":"safe"},"violence":{"filtered":false,"severity":"safe"}},"finish_reason":"stop","index":0,"logprobs":null,"message":{"content":"Got it! How can I assist you today?","refusal":null,"role":"assistant"}}],"created":1739487180,"id":"chatcmpl-B0cMmUvq1nFNAJbXgJCkdbWfpZJQd","model":"gpt-4o-2024-11-20","object":"chat.completion","prompt_filter_results":[{"prompt_index":0,"content_filter_results":{}}],"system_fingerprint":"fp_f3927aa00d","usage":{"completion_tokens":10,"completion_tokens_details":{"accepted_prediction_tokens":0,"audio_tokens":0,"reasoning_tokens":0,"rejected_prediction_tokens":0},"prompt_tokens":18,"prompt_tokens_details":{"audio_tokens":0,"cached_tokens":0},"total_tokens":28}}