Rename and relocate CDC Python examples

Moved the CDC example scripts into the protocol directory and added the .py
suffix. Fixed all references to these scripts.

server/modules/protocol/examples/cdc_last_transaction.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+
+# Copyright (c) 2016 MariaDB Corporation Ab
+#
+# Use of this software is governed by the Business Source License included
+# in the LICENSE.TXT file and at www.mariadb.com/bsl.
+#
+# Change Date: 2019-01-01
+#
+# On the date above, in accordance with the Business Source License, use
+# of this software will be governed by version 2 or later of the General
+# Public License.
+
+import socket
+import hashlib
+import argparse
+import binascii
+import sys
+
+parser = argparse.ArgumentParser(description = "CDC Binary consumer", conflict_handler="resolve")
+parser.add_argument("-h", "--host", dest="host", help="Network address where the connection is made", default="localhost")
+parser.add_argument("-P", "--port", dest="port", help="Port where the connection is made", default="4001")
+parser.add_argument("-u", "--user", dest="user", help="Username used when connecting", default="")
+parser.add_argument("-p", "--password", dest="password", help="Password used when connecting", default="")
+parser.add_argument("-f", "--format", dest="format", help="Data transmission format", default="JSON", choices=["AVRO", "JSON"])
+parser.add_argument("-t", "--timeout", dest="read_timeout", help="Read timeout", default=0)
+parser.add_argument("GTID", help="Requested GTID position", default=None, nargs='?')
+
+opts = parser.parse_args(sys.argv[1:])
+
+sock = socket.create_connection([opts.host, opts.port])
+
+# Authentication
+auth_string = binascii.b2a_hex((opts.user + ":").encode())
+auth_string += bytes(hashlib.sha1(opts.password.encode("utf_8")).hexdigest().encode())
+sock.send(auth_string)
+
+# Discard the response
+response = str(sock.recv(1024)).encode('utf_8')
+
+# Register as a client as request Avro format data
+sock.send(bytes(("REGISTER UUID=XXX-YYY_YYY, TYPE=" + opts.format).encode()))
+
+# Discard the response again
+response = str(sock.recv(1024)).encode('utf_8')
+
+# Register as a client as request Avro format data
+
+if opts.GTID:
+    sock.send(bytes(("QUERY-TRANSACTION " + opts.GTID).encode()))
+else:
+    sock.send(bytes("QUERY-LAST-TRANSACTION".encode()))
+
+response = sock.recv(1024)
+print(response.decode('ascii'))