Rework Parallel Processing in Ordered Mode of S3Queue

Rework parallel processing in Ordered mode of storage S3Queue. This PR is backward incompatible for Ordered mode if you used settings s3queue_processing_threads_num or s3queue_total_shards_num. Setting s3queue_total_shards_num is deleted, previously it was allowed to use only under s3queue_allow_experimental_sharded_mode, which is now deprecated. A new setting is added - s3queue_buckets. #64349 (Kseniia Sumarokova).