contrib/saip-tool: Use repr() on security domain keys

Let's not reinvent the wheel of printing such data structures and use
the repr method provided by the respective class instead.  This also
adds the missing key_usage_qualifier information to the print-out,
as well as the mac_len of the key components.

Change-Id: Iaead4a02f07130fd00bcecc43e1c843f1c221e63

contrib/saip-tool.py

@@ -329,7 +329,7 @@ def do_info(pes: ProfileElementSequence, opts):
         print("Security domain Instance AID: %s" % b2h(sd.decoded['instance']['instanceAID']))
         # FIXME: 'applicationSpecificParametersC9' parsing to figure out enabled SCP
         for key in sd.keys:
-            print("\tKVN=0x%02x, KID=0x%02x, %s" % (key.key_version_number, key.key_identifier, key.key_components))
+            print("\t%s" % repr(key))
 
     # RFM
     print()