[BUGFIX] show uid of reference in show_item.php

The uid of referenced records is not shown anymore and if there are
more items with same title, there is no easy way to identify the
record in the backend.

Solution is to add a column for the uid and page information in the
title attribute of the uid.

Change-Id: I90c44cbff7840888c397d6667ae0a8efa0f5d0a7
Fixes: #33866
Releases: 4.7, 4.6, 4.5
Reviewed-on: http://review.typo3.org/8992
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe
Reviewed-by: Thorsten Kahler
Tested-by: Thorsten Kahler