New strategy isolates all draw/don't draw decisions to the ViewGetLOD
routines, and all dimmed/not dimmed to PCB_RENDER_SETTINGS::GetColor.
The actual drawing in PCB_PAINTER is more-or-less conditon free.
Also adds new layers for pad and via hole walls so that they can be
controlled for high-contrast mode.
Also changes the drawing paradigm so that the pads are drawn even when
not on the high contrast layer, just in low contrast. The hole wall
is drawn in high contrast. This actually makes things clearer to the
user (although to be honest was done to keep from having to re-render
pads when the high contrast layer changes since we have two separate
layers now that we can adjut colours on).
Fixes https://gitlab.com/kicad/code/kicad/issues/7328
The groundwork has now been laid for per sheet instance data. Initially
this only supports sheet page numbers but could be expanded to include
other per sheet instance information.
ADDED: Support for user defined schematic page numbers.
Jeff Young
Dominik Wernberger
Wayne Stambaugh
Marek Roszko