Recognize also I2P addresses in the form `base32hashofpublickey.b32.i2p`
from `CNetAddr::SetSpecial()`.
This makes `Lookup()` support them, which in turn makes it possible to
manually connect to an I2P node by using
`-proxy=i2p_socks5_proxy:port -addnode=i2p_address.b32.i2p:port`
Co-authored-by: Lucas Ontivero <lucasontivero@gmail.com>
This is a backport of core#20685 [7/20]
https://github.com/bitcoin/bitcoin/pull/20685/commits/cff65c4a270887ec171293409ab84f5d0d0be7fc
Depends on D11016