History of Swarm::fetch 2 changes

In crates/flow/src/swarm.rs, lines 151–324 on f4e51e63582d7178ecf5dbcfde1b925a3ef48fe8649810cb68a2a71c46a11c0e. 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.