feat: add snapline plugin

[yvonneyx]

• add snapline plugin
• tests

interface SnaplineOptions extends BasePluginOptions {
  /**
   * <zh/> 对齐精度，即移动节点时与目标位置的距离小于 tolerance 时触发显示对齐线
   *
   * <en/> The alignment accuracy, that is, when the distance between the moved node and the target position is less than tolerance, the alignment line is displayed
   * @defaultValue 5
   */
  tolerance?: number;
  /**
   * <zh/> 对齐线头尾的延伸距离。取值范围：[0, Infinity]
   *
   * <en/> The extension distance of the snapline. The value range is [0, Infinity]
   * @defaultValue 20
   */
  offset?: number;
  /**
   * <zh/> 是否启用自动吸附
   *
   * <en/> Whether to enable automatic adsorption
   * @defaultValue true
   */
  auto?: boolean;
  /**
   * <zh/> 指定元素上的哪个图形作为参照图形
   *
   * <en/> Specifies which shape on the element to use as the reference shape
   * @defaultValue `'key'`
   * @remarks
   * <zh/>
   * - 'key' 使用元素的主图形作为参照图形
   * - 也可以传入一个函数，接收元素对象，返回一个图形
   *
   * <en/>
   * - `'key'` uses the key shape of the element as the reference shape
   * - You can also pass in a function that receives the element and returns a shape
   */
  shape?: string | ((node: Node) => DisplayObject);
  /**
   * <zh/> 垂直对齐线样式
   *
   * <en/> Vertical snapline style
   * @defaultValue `{ stroke: '#1783FF' }`
   */
  verticalLineStyle?: BaseStyleProps;
  /**
   * <zh/> 水平对齐线样式
   *
   * <en/> Horizontal snapline style
   * @defaultValue `{ stroke: '#1783FF' }`
   */
  horizontalLineStyle?: BaseStyleProps;
  /**
   * <zh/> 过滤器，用于过滤不需要作为参考的节点
   *
   * <en/> Filter, used to filter nodes that do not need to be used as references
   * @defaultValue `() => true`
   */
  filter?: (nodeId: string) => boolean;
}

[hustcc]

• fixed Migrate Snapline Plugin #5561