ButtonGroup 按钮组

基本用法

```schema: scope=”body” { “type”: “button-group”, “buttons”: [ { “type”: “button”, “label”: “Button”, “actionType”: “dialog”, “dialog”: { “confirmMode”: false, “title”: “提示”, “body”: “对，你刚点击了！” } },

{
  "type": "button",
  "actionType": "url",
  "url": "https://www.baidu.com",
  "blank": true,
  "label": "百度一下"
},
{
  "type": "button",
  "label": "普通按钮"
}

] }

## 垂直模式
配置`"vertical": true`，实现垂直模式
```schema: scope="body"
[
  {
    "type": "button-group",
    "vertical": true,
    "buttons": [
      {
        "type": "button",
        "label": "按钮1"
      },
      {
        "type": "button",
        "label": "按钮2"
      },
      {
        "type": "button",
        "label": "按钮3"
      }
    ]
  }
]

平铺模式

配置 "tiled": true 实现平铺模式

```schema: scope=”body” [ { “type”: “button-group”, “tiled”: true, “buttons”: [ { “type”: “button”, “label”: “按钮1” }, { “type”: “button”, “label”: “按钮2” }, { “type”: “button”, “label”: “按钮3” } ] } ]

## 按钮主题样式
配置 `btnLevel` 统一设置按钮主题样式，注意 `buttons ` 或 `options` 中的`level`属性优先级高于`btnLevel`。配置 `btnActiveLevel` 为按钮设置激活态时的主题样式。
```schema: scope="body"
[
  {
    "type": "button-group",
    "btnLevel": "light",
    "btnActiveLevel": "warning",
    "buttons": [
      {
        "type": "button",
        "label": "按钮1"
      },
      {
        "type": "button",
        "label": "按钮2"
      },
      {
        "type": "button",
        "label": "按钮3",
        "level": "primary"
      }
    ]
  }
]

属性表