Improve ux for removing forwards

[chiefruds]

Is your feature request related to a problem? Please describe. At the moment you can delete forwards by double clicking or dragging the connection away from the endpoint, not every user knows this is possible so it should be made easier to understand.

Describe the solution you'd like I would like a tooltip when hovering or some other UX solution for removing forwards.

[philipsens]

This could be fixed subsequently by the new way to edit nested elements. #445