地理行政区域json 最新的2019年的。有详细的 三级区域。 编码为六位的 行政编码作为code 110000 等等 如：[{"code":"110000","name":"北京市","children":[{"code":"110100","name":"市辖区","children":[{"code":"110101","name":"东城区","level":2},{"code":"110102","name":"西城区","level":2},{"code":"110105","name":"朝阳区","level":2},{"code":"110106","name":"丰台区","level":2},{"code":"110107","name":"石景山区","level":2},{"code":"110108","name":"海淀区","level":2},{"code":"110109","name":"门头沟区","level":2},{"code":"110111","name":"房山区","level":2},{"code":"110112","name":"通州区","level":2},{"code":"110113","name":"顺义区","level":2},{"code":"110114","name":"昌平区","level":2},{"code":"110115","name":"大兴区","level":2},{"code":"110116","name":"怀柔区","level":2},{"code":"110117","name":"平谷区","level":2},{"code":"110118","name":"密云区","level":2},{"code":"110119","name":"延庆区","level":2}],"level":1}],"level":0},{"code":"120000","name":"天津市","children":[{"code":"120100","name":"市辖区","children":[{"code":"120101","name":"和平区","level":2},