Snap to grid for reads moving between nodes to make it more tube-map-y

[adamnovak]

With the fix for #322, reads are able to curve around freely and don't look as much like the iconic London tube map with its schematic lines and 45 degree angles:

We should probably come up with a way to make the lines look more like that, or like some of the circuit board images from https://www.pcbway.com/blog/Engineering_Technical/Parts_of_a_Circuit_Board.html

We should have all the reads come out straight horizontal for some short distance, then all turn to go at a 45 degree angle, and then all turn back when they get to the height they need to be at.