Create a new stuntsheet based on an existing stuntsheet

[MichaelTamaki]

This will create a new stuntsheet with all dots positions from an existing stuntsheet.

This should automatically set the existing dot’s nextDotId to the new stunt sheet’s dots.

If I remember correctly this is how CalChart 3 does new stuntsheets by default… it makes it easier to create movement based flows (as opposed to creating a blank new stuntsheet, and individually connecting dots between stuntsheets)