ADDED arc, circle and rectangle shapes for schematic. Shapes support
line styles and fill colors.
CHANGED sheet background color in Edit Text & Graphics Properties to
fill color (and it now affects shapes).
Pushed STROKE_PARAMS down into common and moved all shapes to using it
for stroke descriptions.
ADDED Junction Size and Color to Edit Text & Graphics properties.
The added feature is only because it's the only way to recover from
the buggy behaviour having changed all your junctions to overridden
values.
Also adds help texts to the Junction Dot Properties dialog to
specify how to get schematic dot sizes and eeschema colors.
Also fixes the terminology in the Line/Wire/Bus Properties dialog
(the default widths come from the netclasses, not from eeschema).
Fixes https://gitlab.com/kicad/code/kicad/issues/9040
Previously, OnModify() was called for a lot of items, even when not modified.
For large schematics, the calculation time was unreasonable ( several minutes)
It is now called only a few times.