smbd: implement SMB_FILE_NORMALIZED_NAME_INFORMATION handling

smbd: implement SMB_FILE_NORMALIZED_NAME_INFORMATION handling

Windows 10 (1803 and higher) support and use
SMB_FILE_NORMALIZED_NAME_INFORMATION calls over the network. As a
fallback (in case the server don't support it) the client traverses all
path components, which is very expensive.

Implementing SMB_FILE_NORMALIZED_NAME_INFORMATION is very cheap for us
as the open already went through unix_convert() and we have the
information the client is asking for.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13919

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Wed May  1 18:33:00 UTC 2019 on sn-devel-184