Improve global upload performance with R2 Local Uploads

What this post added

Introduced 'Local Uploads' for R2 object storage, allowing data to be written to a storage location close to the client first, then asynchronously copied to the bucket's region. This reduces upload request duration (TTLB) by up to 75% for cross-region uploads. The implementation uses Cloudflare Queues for asynchronous replication tasks and a pull model with a centralized polling service and Gateway Worker for execution. Local Uploads are available for non-jurisdiction restricted buckets.