🚀 Feature: Add `gen_ai.request.model` to data points attributes of meter

Which component is this feature for?

OpenAI Instrumentation

🔖 Feature description

Now the data points attributes of meter only has the attribute gen_ai.response.model but doesn't have gen_ai.request.model. Taking gen_ai.server.time_to_first_token as an example:

Data point attributes:
     -> gen_ai.system: Str(openai)
     -> gen_ai.response.model: Str(moonshot-v1-128k)
     -> gen_ai.operation.name: Str(chat)
     -> server.address: Str(https://api.moonshot.cn/v1/)
     -> stream: Bool(true)

Maybe we should also add it?

🎤 Why is this feature needed ?

Enrich meter attributes

✌️ How do you aim to achieve this?

Similar to the existing attr gen_ai.reponse.model

🔄️ Additional Information

No response

👀 Have you spent some time to check if this feature request has been raised before?

• I checked and didn't find similar issue

Are you willing to submit PR?

Yes I am willing to submit a PR!