Improve performance of S3Queue/AzureQueue

Improve performance of S3Queue/AzureQueue by allowing INSERTs data in parallel (can be enabled with parallel_inserts=true queue setting). Previously S3Queue/AzureQueue can only do first part of pipeline in parallel (downloading, parsing), INSERT was single-threaded. And INSERTs are almost always the bottleneck. Now it will scale almost linear with processing_threads_num. #77671 (Azat Khuzhin). More fair max_processed_files_before_commit in S3Queue/AzureQueue. #79363 (Azat Khuzhin).