use ngram parser for full-text index

### Please make sure of the following things

- [X] I have read the [documentation](https://alist.nn.ci).
- [X] I'm sure there are no duplicate issues or discussions.
- [X] I'm sure this feature is not implemented.
- [X] I'm sure it's a reasonable and popular requirement.

### Description of the feature / 需求描述

Use the `ngram` parser for full-text indexing in versions 5.7 and newer

### Suggested solution / 实现思路

```sql
CREATE FULLTEXT INDEX idx_search_nodes_name ON search_nodes(name) WITH PARSER ngram;
```

### Additional context / 附件

- https://dev.mysql.com/doc/refman/5.7/en/fulltext-search-ngram.html
- https://dev.mysql.com/doc/refman/8.0/en/fulltext-search-ngram.html
- https://dev.mysql.com/doc/refman/8.1/en/fulltext-search-ngram.html