NetworkPkg: Support TCP Cancel function

NetworkPkg: Support TCP Cancel function

This path is used to support TCP Cancel function to abort an
asynchronous connection, listen, transmission or receive request.

If any TCP CompletionToken is not signaled, it should not be closed
directly by calling CloseEvent (Still in the TCP TokenList). If not,
any exception behavior may be triggered. We should cancel it by calling
Tcp->Cancel() first. In such a case, TCP Cancel function is
necessary.

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Zhang Lubo <lubo.zhang@intel.com>
Cc: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>
Cc: Gary Lin <glin@suse.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Gary Lin <glin@suse.com>
Reviewed-by: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>
Tested-by: Gary Lin <glin@suse.com>
Tested-by: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com>