[test] Move MIN_VERSION_SUPPORTED to p2p.py

The messages.py module should contain code and helpers for
[de]serializing p2p messages. Specific usage of those messages should
be in p2p.py. Therefore move MIN_VERSION_SUPPORTED to p2p.py.

Also rename to MIN_P2P_VERSION_SUPPORTED to distinguish it from
other versioning used in Bitcoin/Bitcoin Core.

test/functional/test_framework/messages.py

@@ -31,7 +31,6 @@ import time
 from test_framework.siphash import siphash256
 from test_framework.util import hex_str_to_bytes, assert_equal
 
-MIN_VERSION_SUPPORTED = 60001
 MY_VERSION = 70016  # past wtxid relay
 MY_SUBVERSION = "/python-p2p-tester:0.0.3/"
 MY_RELAY = 1 # from version 70001 onwards, fRelay should be appended to version messages (BIP37)

test/functional/test_framework/p2p.py

@@ -31,7 +31,6 @@ import threading
 from test_framework.messages import (
     CBlockHeader,
     MAX_HEADERS_RESULTS,
-    MIN_VERSION_SUPPORTED,
     msg_addr,
     msg_addrv2,
     msg_block,
@@ -79,6 +78,9 @@ from test_framework.util import (
 
 logger = logging.getLogger("TestFramework.p2p")
 
+# The minimum P2P version that this test framework supports
+MIN_P2P_VERSION_SUPPORTED = 60001
+
 MESSAGEMAP = {
     b"addr": msg_addr,
     b"addrv2": msg_addrv2,
@@ -417,7 +419,7 @@ class P2PInterface(P2PConnection):
         pass
 
     def on_version(self, message):
-        assert message.nVersion >= MIN_VERSION_SUPPORTED, "Version {} received. Test framework only supports versions greater than {}".format(message.nVersion, MIN_VERSION_SUPPORTED)
+        assert message.nVersion >= MIN_P2P_VERSION_SUPPORTED, "Version {} received. Test framework only supports versions greater than {}".format(message.nVersion, MIN_P2P_VERSION_SUPPORTED)
         if message.nVersion >= 70016 and self.wtxidrelay:
             self.send_message(msg_wtxidrelay())
         if self.support_addrv2: