Bug 29454: Use Koha Cache Memory Lite to stash itemtype descriptions for template...

Bug 29454: Use Koha Cache Memory Lite to stash itemtype descriptions for template plugin

Returns empty string if given item type is undefined or unknown

To test:
1 - Add 1000 items to a record, of varying item types
2 - Bring up the details page
3 - Note time to load
4 - Apply patch
5 - Reload page and compare to previous
6 - Confirm information is correct
7 - Confirm some performance benefit

Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>