[FEATURE] Select user functions dialogue in Designer

One thing that I always find myself doing is going back and forth between Perspective/Vision and the Scripting modules in the Designer in order to find custom functions that I want to use but can’t recall the name of or the arguments of.

It would be awesome if there was a dialogue where we could see a list of all user functions and select them, either like the existing intellisense-style that’s there for the system library, or just in a dropdown menu like the expression functions are.