kdc: remove KRB5SignedPath, to be replaced with PAC

kdc: remove KRB5SignedPath, to be replaced with PAC

KRB5SignedPath was a Heimdal-specific authorization data element used to
protect the authenticity of evidence tickets when used in constrained
delegation (without a Windows PAC).

Remove this, to be replaced with the Windows PAC which itself now supports
signing the entire ticket in the TGS key.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14642

[jsutton@samba.org Backported from Heimdal commit
 bb1d8f2a8c2545bccdf2c9179ce9259bf1050086
 - Removed tests
 - Removed auditing hook (only present in Heimdal master)
 - Added knownfails
]

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>