Merge #20564: Don't send 'sendaddrv2' to pre-70016 software, and send before 'verack'

1583498fb6 Send and require SENDADDRV2 before VERACK (Pieter Wuille)
c5a8919660 Don't send 'sendaddrv2' to pre-70016 software (Pieter Wuille)

Pull request description:

  BIP155 defines addrv2 and sendaddrv2 for all protocol versions, but some implementations reject messages they don't know. As a courtesy, don't send it to nodes with a version before 70016, as no software is known to support BIP155 that doesn't announce at least that protocol version number.

  Also move the sending of sendaddrv2 earlier (before sending verack), as proposed in https://github.com/bitcoin/bips/pull/1043. This has the side effect that local address broadcast of torv3 will work (as it'll only trigger after we know whether or not the peer supports addrv2).

ACKs for top commit:
  MarcoFalke:
    ACK 1583498fb6
  jnewbery:
    ACK 1583498fb6
  jonatack:
    ACK 1583498fb6
  vasild:
    ACK 1583498

Tree-SHA512: 3bd5833fa8c8567b6dedd99e4a9b6bb71c127aa66d5284b217503c86d597dc59aa7382c41f3a4bf561bb658b89db81d1a7703a700eef4ffc17cb916660e23a82

test/functional/test_framework/p2p.py

@@ -396,9 +396,9 @@ class P2PInterface(P2PConnection):
         assert message.nVersion >= MIN_VERSION_SUPPORTED, "Version {} received. Test framework only supports versions greater than {}".format(message.nVersion, MIN_VERSION_SUPPORTED)
         if message.nVersion >= 70016:
             self.send_message(msg_wtxidrelay())
-        self.send_message(msg_verack())
         if self.support_addrv2:
             self.send_message(msg_sendaddrv2())
+        self.send_message(msg_verack())
         self.nServices = message.nServices
 
     # Connection helper methods