Updated all events for hidden items and field items (Gen 7)
- Documented and catalogued all hidden items and field items events from games from Gen7.
- Tagged permanently missable items from all lists.
Minor typos may exists, as well as swapped items in USUM.
Also, hidden items and field items are mixed together in Gen7, so there is a change that a field item is actually a hidden item instead.
Please, notify any mistakes at the issues section.