message: UI-QT: added "copy & paste" feature.
  Left-click copies a configuration to clipboard as before, but now right-click inserts this configuration without dragging inbetween.
diff: @@ -459,6 +459,10 @@ void SpinWidget::mousePressEvent(QMouseEvent *event)
  if (this->m_suspended)
  return;
  + if (m_interactionmode == InteractionMode::DRAG)
  + {
  + if (event->button() == Qt::LeftButton)
  + {
  m_previous_mouse_position = event->pos();
  QPoint localCursorPos = this->mapFromGlobal(cursor().pos());
  @@ -467,8 +471,6 @@ void SpinWidget::mousePressEvent(QMouseEvent *event)
  glm::vec2 size{ widgetSize.width(), widgetSize.height() };
  last_drag_coords = system_coords_from_mouse(mouse_pos, size);
  - if (m_interactionmode == InteractionMode::DRAG)
  - {
  m_timer_drag->stop();
  // Copy spin configuration
  Configuration_To_Clipboard(state.get());
  @@ -486,15 +488,27 @@ void SpinWidget::mousePressEvent(QMouseEvent *event)
  m_dragging = true;
  }
  }
  +}
  void SpinWidget::mouseReleaseEvent(QMouseEvent *event)
  {
  if (this->m_suspended)
  return;
  + if (m_interactionmode == InteractionMode::DRAG)
  + {
  + if (event->button() == Qt::LeftButton)
  + {
  m_timer_drag->stop();
  m_dragging = false;
  }
  + else if (event->button() == Qt::RightButton)
  + {
  + dragpaste();
  + this->updateData();
  + }
  + }
  +}
  void SpinWidget::mouseMoveEvent(QMouseEvent *event)
  {
  