LtsWidgets: Qt6 API fixes complete

- QComboBox::activated signal: QString→int parameter (lts_text_editor)
- qAsConst→std::as_const (5 files)
- localPos()→position() (lts_height_plot_widget)
- setMargin→setContentsMargins (tests/window.cpp)
- CMAKE_AUTOUIC OFF + include in header for MOC
- enterEvent(QEnterEvent*) signature fixes
- QRegExp→QRegularExpression replacements

All LtsWidgets module files now Qt6-compatible.

qt6-after/qt6-migrated-legatus/Lts/Common/LtsWidgets/lts_grid_layout.cpp

@@ -25,7 +25,7 @@ LtsGridLayout::LtsGridLayout(LtsWidgets::ButtonSize buttonSize, QWidget *parent,
   setSizeConstraint(SizeConstraint::SetNoConstraint);
   //setHorizontalSpacing(1);
   setVerticalSpacing(1);
-  setMargin(0);
+  setContentsMargins(0, 0, 0, 0);
 }
 
 void LtsGridLayout::add_widget(QWidget *widget)
@@ -64,10 +64,10 @@ void LtsGridLayout::setMaxColumn(int max)
   //resetInternalSize
   m_colSize = 0;
 
-  for (QWidget *wid : qAsConst(m_widgetList))
+  for (QWidget *wid : std::as_const(m_widgetList))
     removeWidget(wid);
 
-  for (QWidget *wid : qAsConst(m_widgetList))
+  for (QWidget *wid : std::as_const(m_widgetList))
     addWidgetInternal(wid);
 
 }