Plot pad outlines on Fab files: fix many issues.

Depending on plotter type and pad type, the plotted shapes were not always the outlines,
but a outline inside the pad shape (due to legacy reasons).
In many cases the plotted shape was in fact incorrect.
(only noticeable for very small pads)
Now the actual pad outlines are plotted without modification.
Fixes #11484
https://gitlab.com/kicad/code/kicad/issues/11484

common/plotters/GERBER_plotter.cpp

@@ -1290,7 +1290,7 @@ void GERBER_PLOTTER::FlashPadCircle( const VECTOR2I& pos, int diametre, OUTLINE_
 
         SetCurrentLineWidth( USE_DEFAULT_LINE_WIDTH );
 
-        Circle( pos, diametre - m_currentPenWidth, FILL_T::NO_FILL, DO_NOT_SET_LINE_WIDTH );
+        Circle( pos, diametre, FILL_T::NO_FILL, DO_NOT_SET_LINE_WIDTH );
     }
     else
     {
@@ -1411,10 +1411,8 @@ void GERBER_PLOTTER::FlashPadRect( const VECTOR2I& pos, const VECTOR2I& aSize,
                 formatNetAttribute( &gbr_metadata->m_NetlistMetadata );
 
             SetCurrentLineWidth( USE_DEFAULT_LINE_WIDTH );
-            Rect( VECTOR2I( pos.x - ( size.x - GetCurrentLineWidth() ) / 2,
-                            pos.y - (size.y - GetCurrentLineWidth()) / 2 ),
-                  VECTOR2I( pos.x + ( size.x - GetCurrentLineWidth() ) / 2,
-                            pos.y + (size.y - GetCurrentLineWidth()) / 2 ),
+            Rect( VECTOR2I( pos.x - ( size.x / 2 ), pos.y - (size.y / 2 ) ),
+                  VECTOR2I( pos.x + ( size.x / 2 ), pos.y + (size.y / 2 ) ),
                   FILL_T::NO_FILL, GetCurrentLineWidth() );
         }
         else
@@ -1483,7 +1481,6 @@ void GERBER_PLOTTER::FlashPadRoundRect( const VECTOR2I& aPadPos, const VECTOR2I&
                                               0, 0, GetPlotterArcHighDef(), ERROR_INSIDE );
 
         SetCurrentLineWidth( USE_DEFAULT_LINE_WIDTH, &gbr_metadata );
-        outline.Inflate( -GetCurrentLineWidth()/2, 16 );
 
         std::vector<VECTOR2I> cornerList;
         // TransformRoundRectToPolygon creates only one convex polygon
@@ -1695,7 +1692,6 @@ void GERBER_PLOTTER::FlashPadCustom( const VECTOR2I& aPadPos, const VECTOR2I& aS
     if( aTraceMode != FILLED )
     {
         SetCurrentLineWidth( USE_DEFAULT_LINE_WIDTH, &gbr_metadata );
-        polyshape.Inflate( -GetCurrentLineWidth()/2, 16 );
     }
 
     std::vector<VECTOR2I> cornerList;