History of Swarm::fetch 2 changes

In crates/flow/src/swarm.rs, lines 151–324 on e20897216221a7410ab42d12ea6161110e26bc8bd1b3f13e31453f1e9ff2aec0. 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.