related https://github.com/spesmilo/electrum/issues/8202
For a HD wallet, instead of checking the first 10 addrs + 10 additional random ones,
we now check the first 10 addrs + 10 random used addrs + 10 random unused addrs.
Checking unused addresses is useful to prevent getting money sent there,
and checking used addresses is useful to inform people of already lost money.