Add sound effects and character scripts

- Imported new sound effects: "Low Boing", "Low Whoosh", and "Pew" with corresponding import files.
- Created a new character script for "Hen" with basic AI and attack functionality.
- Implemented an effect controller script for managing particle effects with one-shot functionality.

scripts/Contents/Characters/Rooster.gd

@@ -22,4 +22,4 @@ func sprint():
 	move(Vector2(
 		Input.get_axis("m_left", "m_right"),
 		Input.get_axis("m_up", "m_down")
-	) * 8, true)
+	) * sprintMultiplier, true)