Improve network weight long hovering

[kkoreilly]

When you long hover over a network weight, it should have some visual feedback to show which weight is being hovered (a change in color/opacity/shininess/texture or a border frame). Ideally the algorithm would also be improved to highlight weights based on their 2D projection relative to your current perspective such that the selected weight would line up with your cursor (the current paradigm only looks at the bases of the weights, which can lead to confusing long hover selection behavior).