Adding support for supplying additional tickets for asktgs

[0xe7]

In order to manually make requests that require additional tickets I've added the /tgs:X argument to asktgs. This allows us to play with these types of request manually, which are primarily used for requesting different types of tickets involved in constrained delegation. An example of usage is below:

C:\temp\dev\Rubeus-additional-ticket\Rubeus\bin\Release>.\Rubeus.exe asktgs /service:cifs/ic1dc1.child1.internal.zeroday.lab /nowrap /dc:idc1.internal.zeroday.lab /ticket:doIFWjCCBVagA...cm9kYXkubGFi /tgs:doIGnjCCBpq...sLnplcm9kYXkubGFi
   ______        _
  (_____ \      | |
   _____) )_   _| |__  _____ _   _  ___
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/
  v1.6.3
[*] Action: Ask TGS
[*] Using domain controller: idc1.internal.zeroday.lab (192.168.71.20)
[*] Requesting default etypes (RC4_HMAC, AES[128/256]_CTS_HMAC_SHA1) for the service ticket
[*] Building TGS-REQ request for: 'cifs/ic1dc1.child1.internal.zeroday.lab'
[+] TGS request successful!
[*] base64(ticket.kirbi):
      doIHVDCCB1...BWS5MQUI=
  ServiceName           :  krbtgt/CHILD1.INTERNAL.ZERODAY.LAB
  ServiceRealm          :  INTERNAL.ZERODAY.LAB
  UserName              :  TestSPN$
  UserRealm             :  INTERNAL.ZERODAY.LAB
  StartTime             :  14/05/2021 00:17:57
  EndTime               :  14/05/2021 10:16:45
  RenewTill             :  21/05/2021 00:16:45
  Flags                 :  name_canonicalize, ok_as_delegate, pre_authent, renewable, forwardable
  KeyType               :  rc4_hmac
  Base64(key)           :  qz+pbRv0EjHVNUUNoCWJiw==

The README is updated with information about the /tgs:X argument as well as the /usesvcdomain related switch which is useful to force the domain to be extracted from the given SPN when using a /tgs:. Also bumps the minor version.

[HarmJ0y]

Looks great (as always), landed!