Changed day from enum to string, so frontend can easily display the days in Norwegian

Day should now be sendt in norwiegan for display in frontend

src/main/java/edu/ntnu/idatt210602/matsvinnbackend/model/DayMenu.java

@@ -20,15 +20,5 @@ public class DayMenu {
 
     @Setter @Getter @ManyToOne Recipe recipe;
 
-    @Setter @Getter Day day;
-
-    public enum Day{
-        MONDAY,
-        TUESDAY,
-        WEDNESDAY,
-        THURSDAY,
-        FRIDAY,
-        SATURDAY,
-        SUNDAY
-    }
+    @Setter @Getter String day;
 }