tests: Add 2 tests for unique fileid's with top bit set (generated from itime) for...

tests: Add 2 tests for unique fileid's with top bit set (generated from itime) for files and directories.

smb2.fileid_unique.fileid_unique
smb2.fileid_unique.fileid_unique-dir

Create 100 files or directories as fast as we can
against a "normal" share, then read info on them
and ensure (a) top bit is set (generated from itime)
and (b) uniqueness across all generated objects
(checks poor timestamp resolution doesn't create
duplicate fileids).

This shows that even on ext4, this is enough to
cause duplicate fileids to be returned.

Add knownfail.d/fileid-unique

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14928

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Christof Schmitt <cs@samba.org>
(cherry picked from commit 30fea0d31117c1a899cd333a9b8a62ba765dbb02)