Introduce a new message `sendaddrv2` to signal support for ADDRv2. Send the new message immediately after sending the `VERACK` message. Add support for receiving and parsing ADDRv2 messages. Send ADDRv2 messages (instead of ADDR) to a peer if he has advertised support for it.
Partial backport (3/4) of core PR19954:
Depends on D9199.
Some functional tests required a debug log message update since we where
using a slightly different form from core. The new code is in sync with
core's message to make later backports easier.