Allowing Filter on Tags

Im trying to enable filter on tags and have the following config:

```
{
"settings": {
"showFilter": true,
"showArrows": true,
"showTags": true
},
"fields": [
{
"name": "System.AreaPath",
"title": "Area",
"filter": true
},
{
"name": "System.IterationPath",
"title": "Iteration",
"filter": true
},
{
"name": "System.Tags",
"title": "Tags",
"filter": true
},
{
"name": "Microsoft.VSTS.Scheduling.Effort",
"title": "Effort"
}
]
}
```

Ive tried with and without `"showTags": true` but to no effect. With `"showTags": true` the tags appear on the cards, but not filterable. Without `"showTags": true` no tags are shown on the card or on the filters.

Any ideas @edtro?

首先，在启用 showTags 和 System.Tags 的情况下，复现 Query Based Boards Azure DevOps 扩展中的配置。验证标签在卡片上的显示方式，以及它们是否出现在筛选控件中；完成的标准是可以筛选标签，同时保留现有的卡片显示行为。

由索引模型根据 Issue 内容生成。