server : fix logprobs, make it OAI-compatible (#10783)
* server : fix logprobs, make it openai-compatible
* update docs
* add std::log
* return pre-sampling p
* sort before apply softmax
* add comment
* fix test
* set p for sampled token
* update docs
* add --multi-token-probs
* update docs
* add `post_sampling_probs` option
* update docs [no ci]
* remove --multi-token-probs
* "top_probs" with "post_sampling_probs"
* resolve review comments
* rename struct token_prob to prob_info
* correct comment placement
* fix setting prob for sampled token
