Add complete import support for PADS ASCII (.asc) files, covering both
PCB layouts and schematics. The importer handles board outlines, copper
pours, routing with via inference, footprint decals, net assignment,
design rules, and component placement for PCB files. For schematics, it
supports symbol building from CAEDECAL definitions, multi-gate and
multi-variant parts, power symbols, wire routing, net labeling, arc
graphics, title blocks, and hierarchical sheet connectivity.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/19944
Seth Hillbrand
0e7a052af0