Forwards rework

[philipsens]

Forwards

Label position

Problem

Labels on long forwards are difficult to read and require a lot of pan-zooming.

Solution

Add the label just a bit after and before the connection circles on both sides.
If possible, only one in the middle if the forward is really short.

Connection circles

Problem

In zoomed-out mode, the circles are difficult to see. And when merged, it is not possible to see the difference.

Solution

Add the colors to the labels. When wanting to drag a new forward, the dropdown can be used.

Originally posted by @philipsens in #507

[stijnpotters1]

two labels instead of 1.
One label when close to eachother

merge later in the edge when zoomed out nodes,
so the new labels wont be merged when zoomed out