Add the Enum classes FoodItem and MeasuringUnit

src/main/java/no/ntnu/idatt1002/demo/data/recipes/FoodItem.java

+package no.ntnu.idatt1002.demo.data.recipes;
+
+public enum FoodItem {
+
+    ONION("onion"),
+    MINCED_MEAT("minced meat"),
+    POTATO("potatoes"),
+    YELLOW_CHEESE("yellow cheese"),
+    WHEAT_FLOUR("wheat flour"),
+    MILK("milk"),
+    TOMATO("tomato"),
+    ORANGE("orange"),
+    LEMON("lemon"),
+    SALSA_SAUCE("salsa sauce")
+    ;
+
+    public final String label;
+
+    FoodItem(String label) {
+        this.label = label;
+    }
+}

src/main/java/no/ntnu/idatt1002/demo/data/recipes/MeasuringUnit.java

+package no.ntnu.idatt1002.demo.data.recipes;
+
+public enum MeasuringUnit {
+
+    DL("dl."),
+    L("l."),
+    TSP("tsp."),
+    TBS("tbs."),
+    GR("gr."),
+    KG("kg.");
+
+    public final String label;
+
+    MeasuringUnit(String label) {
+        this.label = label;
+    }
+}