[WINSTA] Add some missing stubs (#2307)

Add stubs for WinStationCanLogonProceed() and _WinStationOpenSessionDirectory() functions to make winlogon from Windows Server 2003 happy.

CORE-15392 CORE-16458

dll/win32/winsta/logon.c

@@ -111,3 +111,18 @@ WINSTAAPI _WinStationNotifyLogon(PVOID A,
 {
     UNIMPLEMENTED;
 }
+
+VOID
+WINSTAAPI WinStationCanLogonProceed(PVOID A,
+                                    PVOID B,
+                                    PVOID C)
+{
+    UNIMPLEMENTED;
+}
+
+VOID
+WINSTAAPI _WinStationOpenSessionDirectory(PVOID A,
+                                          PVOID B)
+{
+    UNIMPLEMENTED;
+}