[Feature]: reasoning_tokens in Chat Completion Response usage

[chaunceyjiang]

The PR implements OpenAI's new API and adds the number of reasoning token stats for each request.

usage: {
  total_tokens: 2306,
  prompt_tokens: 2006,
  completion_tokens: 300,
  
  prompt_tokens_details: {
    cached_tokens: 1920
  },
  completion_tokens_details: {
    reasoning_tokens: 0
  }
}

FIX #14335

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[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @chaunceyjiang.

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[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @chaunceyjiang.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork