History of Swarm::fetch 2 changes

In crates/flow/src/swarm.rs, lines 151–324 on 89171fca079c76d2eeee185ded4654827fea8834b4e6c5fdc2a337465af1e43f. 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 151,324:crates/flow/src/swarm.rs.