use edge animation

[forresto]

Now that the-graph-editor has an edge animation api, we should decide when to trigger it.

[chadrik]

+1

[bergie]

Two cases where this might be good to use:

• There are packets on the edge that user hasn't seen yet (the packet inspector not open, etc)
• When hovering over that edge's packets / edge inspector (to highlight "this is the edge you're looking at")