iceberg: cut shredder allocations, and add write/commit performance harnesses - #4712

iceberg: cut shredder allocations, and add write/commit performance harnesses#4712

Jeffail wants to merge 12 commits into

mainredpanda-data/connect:mainfrom

iceberg-shredder-allocations-and-benchesredpanda-data/connect:iceberg-shredder-allocations-and-benchesCopy head branch name to clipboard