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
This changes the file format. All previous copper layers that had a user
defined name are forced back to the canonical name and the user defined
name is stored as an optional quoted string in the layer definition and
only used for UI and plotting purposes. All copper object layer names
are now the canonical name for internal file use.
ADDED: Nine new user definable non-copper layers that can be optionally
added to the board layer stack.
CHANGED: All board layers can now be renamed by the user.
CHANGED: User defined layer names can now contain space characters.
Fixes https://gitlab.com/kicad/code/kicad/issues/1969
LayerName() can now be called to get the default, translatable name
for any board layer. LSET::Name() is used for the untranslated
names required for parsing board files.