Implement "Not A Picky Eater" trait functionality

- Rename "Unpicky Eater" to "Not a Picky Eater"
- Wrap around the `ISEatFoodAction:perform` and `ISToolTipInv:render`
methods, adjusting unhappiness and boredom increase if the trait is
present.
- Reorganize files

media/lua/shared/Translate/EN/UI_EN.txt

@@ -1,4 +1,4 @@
 UI_EN = {
-    UI_trait_UnpickyEater = "Unpicky Eater",
-    UI_trait_UnpickyEater_description = "Eating never increases unhappiness or boredom.",
+    UI_trait_NotAPickyEater = "Not a Picky Eater",
+    UI_trait_NotAPickyEater_description = "No foods make you unhappy or bored.",
 }