Add the locations selector (closes #153)

module/models/Item/CommonItemData.mjs

@@ -42,16 +42,8 @@ export class CommonItemData extends foundry.abstract.TypeDataModel {
 				nullable: false,
 			}),
 			location: new fields.StringField({
-				initial: null,
-				nullable: true,
-				/*
-				"equipped" = on player, actively having an effect (e.g. armour
-					is worn, weapon is held), not all items have an equipped state
-				"inventory" = on player, equivalent to being put in a backpack
-				"storage" = not on player at all, in a chest in their house or
-					smth, these items should be displayed in the storage tab
-				*/
-				choices: ["equipped", "inventory", "storage"],
+				initial: "",
+				nullable: false,
 			}),
 		};
 	};