[NETAPI32] Implement DsGetSiteNameA

Also add the NetpAllocAnsiStrFromWStr helper function.

dll/win32/netapi32/misc.c

@@ -135,6 +135,38 @@ NetUnregisterDomainNameChangeNotification(
 }
 
 
+PSTR
+WINAPI
+NetpAllocAnsiStrFromWStr(
+    _In_ PWSTR InString)
+{
+    UNICODE_STRING UnicodeString;
+    ANSI_STRING AnsiString;
+    ULONG Size;
+    NET_API_STATUS NetStatus;
+    NTSTATUS Status;
+
+    RtlInitUnicodeString(&UnicodeString, InString);
+
+    Size = RtlUnicodeStringToAnsiSize(&UnicodeString);
+    NetStatus = NetApiBufferAllocate(Size,
+                                     (PVOID*)&AnsiString.Buffer);
+    if (NetStatus != NERR_Success)
+        return NULL;
+
+    Status = RtlUnicodeStringToAnsiString(&AnsiString,
+                                          &UnicodeString,
+                                          FALSE);
+    if (!NT_SUCCESS(Status))
+    {
+        NetApiBufferFree(AnsiString.Buffer);
+        return NULL;
+    }
+
+    return AnsiString.Buffer;
+}
+
+
 PWSTR
 WINAPI
 NetpAllocWStrFromAnsiStr(