Page layout editor: Fix bitmap bounding box

Fixes https://gitlab.com/kicad/code/kicad/issues/7315

common/page_layout/ws_draw_item.cpp

@@ -448,10 +448,6 @@ const EDA_RECT WS_DRAW_ITEM_BITMAP::GetBoundingBox() const
     auto*    bitmap = static_cast<const WS_DATA_ITEM_BITMAP*>( m_peer );
     wxSize bm_size = bitmap->m_ImageBitmap->GetSize();
 
-    // bm_size is in Eeschema unit (100nm), convert to iu (0.001 mm)
-    bm_size.x /= 10;
-    bm_size.y /= 10;
-
     EDA_RECT bbox;
     bbox.SetSize( bm_size );
     bbox.SetOrigin( m_pos.x - bm_size.x/2, m_pos.y - bm_size.y/2 );

pagelayout_editor/pl_draw_panel_gal.cpp

@@ -107,6 +107,7 @@ void PL_DRAW_PANEL_GAL::DisplayWorksheet()
     dummy.SetPaperFormat( &m_edaFrame->GetPageSettings().GetType() );
     dummy.SetTitleBlock( &m_edaFrame->GetTitleBlock() );
     dummy.SetProject( &m_edaFrame->Prj() );
+    dummy.SetMilsToIUfactor( IU_PER_MILS );
 
     for( WS_DATA_ITEM* dataItem : model.GetItems() )
         dataItem->SyncDrawItems( &dummy, m_view );

pagelayout_editor/pl_editor_frame.cpp

@@ -850,7 +850,7 @@ WS_DATA_ITEM* PL_EDITOR_FRAME::AddPageLayoutItem( int aType )
         }
 
         // Set the scale factor for pl_editor (it is set for eeschema by default)
-        image->SetPixelSizeIu( 25400.0 / image->GetPPI() );
+        image->SetPixelSizeIu( IU_PER_MILS * 1000.0 / image->GetPPI() );
         item = new WS_DATA_ITEM_BITMAP( image );
     }
     break;