More options for connector generation

[yawkat]

https://www.printables.com/model/1579487-gridflock-gridfinity-baseplate-generator/comments/3383221

I think the edge generation might be nicer if edge segments could alternate male and female, so that way any 2 edges with that gadget on it could be fit together. Or have pieces that are all-female and pieces that are all-male. The solid edges at the end of a design could have all-female edges so later expansions on the edges could work, perhaps with a connector piece for more stability.