UI feature request: program call graph tab

[m4b]

It would be really cool if we had another tab which displayed the program's call graph.

Specifically, it would be nice if:

1. functions are nodes in a connected graph; each node is scaled by how many different functions call it.
2. function with the most "is called" number is the largest node in the displayed network (and perhaps displayed in the center)
3. Hovering over a node displays how many it calls, and how many its called by
4. Click on a node displays in a side tab which functions call it, and which functions it calls

I frequently want this information just when I'm debugging my program, let alone binary analysis stuff, so I think it would be really handy :)

[flanfly]

My failed attempts creating a call graph are documented in #87. The whole issue is on hold until my frustration has cooled down 🤣. Feel free.