addr: standardized common (?) address size optimization

[Roasbeef]

When making an address, it's possbile that the internal key and the script key are actually the same. In this case, the addresses can shrink a bit.

Compare this address: tarot1qqqsqq3qkq8t3c55q37cptr6jpuf3k8kw6dcvdf9xtf0rt9hdldpu369rersgg9q4l43vhcwcd5gpd5wpw4tmxkeccharf564xvtcv8f5drzqts83urzpg90avt97rkrdzqtdrst427e4kwx9lg6dx4fnz7rp6drgcszupu0pqplmmkdmyfuej

To this one (only encodes script key): tarot1qqqsqq3qtv7gupgd4lec2gpzpkcywm33823lqlh0a8utxuz80sa2a2a68p5sgg9q4l43vhcwcd5gpd5wpw4tmxkeccharf564xvtcv8f5drzqts83uyq8lwv4qhv5ul6