Printing multiple bitmaps

A long-standing issue with multiple workarounds
(https://gitlab.com/kicad/code/kicad/-/issues/1877) prevented eeschema
printouts with multiple images or images in both the worksheet and the
schematic.

We worked around this by ordering the bitmap printing to be the first
step in the printing process.  This partially worked but didn't get
everything correct.  The primary difficulty in debugging this was that
the wxPrintPreview that we generate looked correct.  Only the actual
printout was incorrect.

The fix is to explicitly clip bitmap drawing to the bitmap area,
regardless of how large the bitmap is.

common/bitmap_base.cpp

@@ -269,8 +269,13 @@ void BITMAP_BASE::DrawBitmap( wxDC* aDC, const wxPoint& aPos )
 
         pos.x  = KiROUND( pos.x / GetScalingFactor() );
         pos.y  = KiROUND( pos.y / GetScalingFactor() );
+        size.x = KiROUND( size.x / GetScalingFactor() );
+        size.y = KiROUND( size.y / GetScalingFactor() );
     }
 
+    aDC->DestroyClippingRegion();
+    aDC->SetClippingRegion( pos, size );
+
     if( GetGRForceBlackPenState() )
     {
         wxBitmap result( m_bitmap->ConvertToImage().ConvertToGreyscale() );
@@ -288,6 +293,8 @@ void BITMAP_BASE::DrawBitmap( wxDC* aDC, const wxPoint& aPos )
         aDC->SetUserScale( scale, scale );
         aDC->SetLogicalOrigin( logicalOriginX, logicalOriginY );
     }
+
+    aDC->DestroyClippingRegion();
 }