Improve class Item, by enumeration ItemType

[verhagen]

⚠️ First resolve #162

Create enumeration ItemType

It should contain, all the types of Items, that are currently found in the game, like:

ARMOUR
FOOD
FOOD_LIQUID
TOOL
WEAPON
etc

Update Item
Inside class Item, there is a field type, of type String, change it to:

private ItemType type

Update the related code.

[projectdelphai]

1. There is no distinction between food and food_liquid. It's all food to the user in that it provides +n amount of hp. If this absolutely needs to be changed (i.e to differentiate in grammar when posting status updates (eat vs drink)) it should be changed to drink or potion.
2. A better option is to include liquids as potions, items which modify stats positively or negatively. So pmil1 would provide +5 hp while pmil2 would give +20 hp for example while ptox1 (toxic potion lvl 1) would give -30 hp.

[verhagen]

The idea is to have a command eat for fixed food and drink for liquid stuff.

[paddatrapper]

That can be done through the use of aliases and would not need the distinction made in the item type. Aliases can simply added to use command for East and drink

[projectdelphai]

We can just change food-liquids to potions and then filter based on itemType. If it's food, then eat and if it's potion, then drink.