Add circle timer

scripts/hydroponics_station/state/growing.gd

@@ -16,9 +16,10 @@ func enter_from(state):
 	ctx.get_node("grow_timer").start()
 	ctx.status_light.activate()
 	ctx.item_dump.enabled = false
+	ctx.get_node("circle_timer").set_timer(ctx.get_node("grow_timer"))
 
 func exit_to(state):
-	pass
+	ctx.get_node("circle_timer").clear_timer()
 
 func on_coin_machine_coin_requirement_met(player):
 	assert(false, "coin machine should be disabled while growing")