Convex Hull node

This node should convert vector shapes into convex hulls of their shapes, preserving their convex curves and bridging their concave parts with straight lines.

~~@Keavon Just wanted a run-down of how you want this to work. I'll be implementing a standard algorithm but wanted to ask if you had any specific functionality in mind.~~

~~Edit:
Information for whoever wants to tackle this task:~~

~~While there is plenty of literature about building the convex hull from polygons (polylines), there is much less on the internet about algorithms for doing that from bezier curves. You'll have to do some additional research to solve this, either through Googling for online resources or reading academic papers or thinking through a solution to the problem yourself as an extension of one of the polyline algorithms. The same algorithm needs to work for both shapes such as a hexagon and a circle.~~

No files, tests, or entry points are named. Start by locating the vector-shape node implementation, then research convex-hull algorithms for polygons and Bézier curves; done means one algorithm handles both polygonal shapes such as hexagons and curved shapes such as circles, preserving convex curves and bridging concave parts with straight lines.

Written by the indexing model from the issue text.