When building the connectivity database, we should not be using the
connectivity to check for shapes.
To make this deterministic, we introduce two flags (ALWAYS_FLASH and
NEVER_FLASH) that are used with connectivity building to determine
whether a pad is flashed for connectivity or not. ZONE <-> PAD/VIA
connectivity will be checked with ALWAYS_FLASHED and all other
connectivity will be checked with NEVER_FLASHED if they are marked for
potential annular ring removal. If they are not marked for removal,
they will be checked ALWAYS_FLASHED.
Fixes https://gitlab.com/kicad/code/kicad/issues/11114
Jeff Young
Seth Hillbrand
jean-pierre charras