I need a Skript that will handle countdowns and display them on the Boss Bar. It should allow for customizable countdown times with commands like /countdown start 10m 30s, and so on. Additionally, there should be a command to toggle the countdown display on or off, like /togglecount. Furthermore, the Skript should allow specifying which player's Boss Bar will show the countdown with a command such as /countdown start 10m 30s %player_name%.