Rebase items (Item class) creation.

Extend creation of Equipment for using pre-defined records. Add notifications for inventory operations like putting too much weight into or while trading not enough cash information. Remove version of Item constructor where first argument can be instance of Item class. Add some jsDocs. Recreate putting items into Game inventories.

Add new way of creation of Items. './global/items.js' contains 'createItem()' function and 'const items' object. This two together is all you need for creation of items from now.