Add Canvas Component Dragging API

[mohamedsalem401]

• For dragging symbols

  const onDragStart = () => {
  Canvas.startSort([{
    symbolModel: symbol,
    content: () => Components.addSymbol(symbol),
    definition: {
      type: symbol.get('type'),
      draggable: symbol.attributes.draggable,
      droppable: symbol.attributes.droppable,
    },
  }]);
  };
  
  const onDragEnd = () => {
  Canvas.endSort();
  };

• Also add a property to blocks that determines if a block can be moved inside a given component when the content is a function.