Fixes#12580
Additionally does not export no_connect netlist annotation on pins
which are both connected to another pin and a NC item, unless all
connected pins are stacked at the symbol level.
Adds testing of pin types to netlist QA unit tests.
(cherry picked from commit 9dca70a773)
Same pin name != same net name unless the pins are explicitly connected
Also add pin number to all unconnected pads ensuring they have unique
nets
Fixes https://gitlab.com/kicad/code/kicad/issues/13236
JamesJCode
Seth Hillbrand
Jeff Young
Roberto Fernandez Bautista
Sylwester Kocjan