Struct DownloadStallTimeoutOption (2.19.0)

If a download stalls, i.e., no bytes are received for a significant period, it may be better to restart the download as this may indicate a network glitch.

For large requests (e.g. downloads in the GiB to TiB range) this is a better configuration parameter than a simple timeout, as the transfers will take minutes or hours to complete. Relying on a timeout value for them would not work, as the timeout would be too large to be useful. For small requests, this is as effective as a timeout parameter, but maybe unfamiliar and thus harder to reason about.