Add a switch to hide item description

[seflerZ]

The item list contains title and description by default. Sometimes the description is not necessary. I've looked into the source code and found the description was rendered in item_list_view_update_item_internal() method in "src/ui/item_list_view.c". To disable it, we can simply add a switch there. Below is the part of source code

if (ilv->wideView) {
                const gchar *important = _(" <span background='red' color='black'> important </span> ");
                gchar *teaser = item_get_teaser (item); // <-- Change HERE
                gchar *tmp = title;

[seflerZ]

We can add a switch in Tile tab of Preference, just like the default view mode. If that's ok, I'll try to implement the code.