History of Swarm::fetch 3 changes

In crates/flow/src/swarm.rs, lines 151–341 on f3b5b86e23ef1fa5ed4c34c1d67951fc40cc765648fbb2571232add4eeec4406. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 151,341:crates/flow/src/swarm.rs.