Add local difficulty api

purpur-api/paper-patches/files/src/main/java/org/bukkit/World.java.patch

@@ -0,0 +1,19 @@
+--- a/src/main/java/org/bukkit/World.java
++++ b/src/main/java/org/bukkit/World.java
+@@ -4246,6 +_,16 @@
+     @Nullable
+     public DragonBattle getEnderDragonBattle();
+ 
++    // Purpur start
++    /**
++     * Gets the local difficulty (based on inhabited time) at a location
++     *
++     * @param location Location to check
++     * @return The local difficulty
++     */
++    public float getLocalDifficultyAt(@NotNull Location location);
++    // Purpur end
++
+     /**
+      * Get all {@link FeatureFlag} enabled in this world.
+      *