Function test_bridges

async fn test_bridges(
    bridge_lines: &[String],
    common_tor_client: TorClient<PreferredRuntime>,
) -> (HashMap<String, BridgeResult>, HashMap<String, Arc<Channel>>)

Contains the main logic for testing each bridge.

It ends up taking in a slice of bridge lines, and creates MAX_CONNECTIONS number of connections as tasks, then waits for these requests to be resolved, either by successfully connecting or not (for a variety of reasons). The actual work to check each single bridge is done by is_bridge_online()

This is done up until all the bridges in the slice are covered