Implement stream_options.include_usage for OpenAI-compatible chat completions streaming#29

Copilot wants to merge 2 commits intomasterericcurtin/llama.cpp:masterfrom

copilot/fix-d7a91a3a-311f-46e0-b7bd-29ac3fe5352fericcurtin/llama.cpp:copilot/fix-d7a91a3a-311f-46e0-b7bd-29ac3fe5352fCopy head branch name to clipboard