Implement aria2-style multi-connection download in common_download_file_single#34

Copilot wants to merge 3 commits intomasterericcurtin/llama.cpp:masterfrom

copilot/fix-89d7b352-a424-4065-9297-7f8d4257fa8bericcurtin/llama.cpp:copilot/fix-89d7b352-a424-4065-9297-7f8d4257fa8bCopy head branch name to clipboard