UNDER REVIEW [YLD-18810] Player can use multiple tiles of the same button event in custom window

[Adam Snellgrove 1451]

As originally posted by @Fompster https://ylands.com/community/topic/25586-yld-18769-custom-window-scripting/

When you create some button in a custom window, you can then drag it from the list in the custom window script multiple times. It should grey out when you use one.