Remove API of history plugin from Graph #5317

The History is a independent plugin, which API should not mounted on the Graph class.

It provides API calls through the following example:

import { Extensions } from '@antv/g6';

const history = new Extensions.History({
  key: 'history-1',
});

const graph = new Graph({
  // ...
});

graph.setOption({
  widgets: [history],
  // ...
});

history.redo();