Weapon FR: Imperfect beam tracking/leading of moving targets.

Isolated and salvaged from #2412 now that most of that request is effectively implemented

With the goal of visually impressive and fun anti-fighter weapons, I end up wanting to 'telegraph' a beam attack and make it selectively imperfect in it's tracking.

Effectively, what I want is a beam that sweeps towards a moving target and follows it, but allows a window to dodge.
The way I imagine that working is, using a type 5 beam, you would have to essentially define a curve for how much the beam leads the target. So imagine a beam that activates aiming somewhere away from the target, and takes 2 seconds to sweep to the center and hit the target. You would define that it starts off projecting the target's position two seconds ahead and then lets that number head count down as it moves. But I also want to have a point where it stops following the player's actual movement and keeps tracking as if the player was moving in a straight line. For some beams that would be almost immediate, for some it would be at the last possible moment.
I may be wanting too much paramaterization but I really feel like there's a lot of possibilities for tuning and creativity here, and having sane defaults alone won't open that door very wide.