Bug 24701: Add column config to course_items_table

Bug 24701: Add column config to course_items_table

This patch adds course_items_table to the column config tool
TEST PLAN:
1. Have some course reserves
2. Add some items to that course reserve and browse to opac-course-details
2. See all the unconfigurable columns
3. Apply patch
4. Browse to column config > OPAC > opac-course-details
5. Try hiding each column and make sure the correct column is hidden on opac-course-details.pl

Signed-off-by: Devinim <kohadevinim@devinim.com.tr>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>