Footprint-based pin mapping

Pin Mapping can also be driven directly from a schematic symbol rather than through the Connectivity Hub pin-list panels:

1. Select a pin on the symbol.
2. Map the pin.

This works because the symbol is associated with the footprint connector library part — selecting a pin on the symbol resolves to the corresponding pin on that library part, so the mapping can be made right from the schematic view instead of switching to the Connectivity Hub tab.