Labels on traces and wires

[KjellMorgenstern]

Problem

Right now, displaying a label on a wire is only possible by adding text logo items.
These have to be placed and named manually.
Wires can be named, but this name is only displayed on mouse over , or in the Inspector.

Proposed Solution

Enable labels for wires, that are automatically placed.
Possible placements options could be:

onto

along

manual

This is the default behavior of Fritzing part label items.
After the initial placement (top right), the label can be rotated and moved.

[KjellMorgenstern]

Related to #3634