Edge's tooltip is not shown if you hover too far from the edge, even if you are still on edge handle

[Djazouli]

Describe the bug The overlay for the edge is only created over the edge path, but not the edge handle. This means that if you have a big edge handle, and you hover on a side of it, outside edge's path, the tooltip will not show.

To Reproduce Steps to reproduce the behavior:

1. Select the base example, change the SpecialEdgeShape to: <symbol viewBox="0 0 154 154" id="specialEdge">
2. Hover on the top or bottom of the edge handle.
3. The tooltip will not appear (see screenshot)

Expected behavior I think the tooltip should appear, as it appears when you hover over the rest of the edge.

Screenshots If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information): OS: macOS Catalina v10.15.5 Browser: Brave Version 1.10.97 Chromium: 83.0.4103.116 (Official Build) (64-bit)

Additional context Add any other context about the problem here.