Make queyr Cross-lingual expansion configurable?

It is nice to expand query keywords cross-lingual, but could we make it configurable?

```
<KEYWORDS_ALT>
{"迷你ST": 9, "标准/完整ST语言": 7, "语言比较": 4}
</KEYWORDS_ALT>
10:34:37 AM[Probe:Keywords] Cross-lingual alt: ['迷你ST', '标准/完整ST语言', '语言比较']
```