test: Fix intermittent failure in rpc_net.py --v2transport

Make sure that v2 handshake is complete before comparing getpeerinfo
outputs so that `transport_protocol_type` isn't stuck at 'detecting'.

- on the python side, this is ensured by default
`wait_for_handshake = True`  inside `add_p2p_connection()`.
- on the c++ side, add a wait_until statement till
`transport_protocol_type = v2`  so that v2 handshake is complete.

Co-Authored-By: Martin Zumsande <mzumsande@gmail.com>

test/functional/rpc_net.py

@@ -113,6 +113,8 @@ class NetTest(BitcoinTestFramework):
         self.nodes[0].setmocktime(no_version_peer_conntime)
         with self.nodes[0].wait_for_new_peer():
             no_version_peer = self.nodes[0].add_p2p_connection(P2PInterface(), send_version=False, wait_for_verack=False)
+        if self.options.v2transport:
+            self.wait_until(lambda: self.nodes[0].getpeerinfo()[no_version_peer_id]["transport_protocol_type"] == "v2")
         self.nodes[0].setmocktime(0)
         peer_info = self.nodes[0].getpeerinfo()[no_version_peer_id]
         peer_info.pop("addr")