feat(rules): Client side information consequence in rules

**Summary**

With the release of the merchandising UI, the need to control UI aspects using the QR is growing and the rules API needs to expose fields to store information to perform specific client side tasks in a structured way.

The new consequence `consequence.renderingContent` contains a json object where each top level attribute is restricted to known use cases. The currently identified use cases are:
- Redirect
- Facet merchandising / ordering
- User defined data

Each top level excepted the `userData` one have a schema which is enforced and strict and customers can add metadata using the `userData` object:

```json
{
"condition": {
"anchoring": "is",
"pattern": "samsung"
},
"consequence": {
"renderingContent": {
"redirect": {
"url": "https://algolia.com/samsung" // required by the API
},
"facetMerchandising": {
"order": [ "brand", "price"] // required by the API
},
"userData": {
"callback": "displayBrand(samsung)" // optional field defined by user
}
}
}
}
```

This information will be returned in a structured way in the path `rules.consequence` of the search response:

```json
{
"hits": [...],
[...],
"query": "samsung",
"rules": {
"consequence": {
"renderingContent": [ // Array containing the content of matching rules
{
"facetMerchandising": {
"order": [
"brand",
"price"
]
},
"redirect": {
"url": "https://algolia.com/samsung"
},
"userData": {
"callback": "displayBrand(samsung)"
}
}
]
}
},
"userData": [ // Legacy userData
{
"myUserData": {}
}
]
}
```

Internal specs issue: [#152](https://github.com/algolia/algoliasearch-client-specs-internal/issues/152)

从内部 specs issue #152 开始，跟踪 rules.consequence 在搜索响应中的表示方式。确认 redirect、facetMerchandising 和 userData 结构（包括严格字段和元数据）是否以 issue 中描述的 renderingContent 数组形式公开。

由索引模型根据 Issue 内容生成。