Bug 27164: Fix item search CSV export

Bug 27164: Fix item search CSV export

In item search CSV export, data cells are exported with double quotes.
There should also be double quotes in header cells.
Also some spaces can be removed.
Delimiter must be from system preference 'delimiter'.
TT filter must be $raw not html, only double quotes must be espaped by
duplication of it.

This may help to open the CSV with any table/calc software.

Test plan :
1.0) Create a record with title : Laurel & "Hardy"
1.2) Create an item on this record
2.0) Without patch
2.1) Perform an item search on title 'Laurel'
2.2) Export as a CSV file and save the file locally
2.3) Open the file with a table/calc software
3.0) Apply patch
3.1) Perform same item search
3.2) Export as a CSV file and save the file locally
3.3) Open the file with a table/calc software
4.0) Compare files with diff/meld
=> you see double quotes arround header cells
   and removal of space after coma
4.1) Check that delimiter is from system preference 'delimiter'
4.2) In table/calc software they should look the same

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>