[Compatibility] Non-ASCII (Chinese) column alias without backticks fails to parse

## Summary
A non-ASCII (Chinese) column alias without backticks fails to parse. MySQL accepts unquoted non-ASCII aliases.

## Environment
- **Reported on:** MatrixOne Cloud free tier, `8.0.30-MatrixOne-v3.0.11`
- **Retested on:** local Docker `matrixorigin/matrixone` **main branch** build, Git commit `0bfda60` (built 2026-05-30), version string `8.0.30-MatrixOne-v`

## Test case
```sql
SELECT 1 AS 中文别名; -- fails
SELECT 1 AS `中文别名`; -- works
```

## Actual result
```
ERROR 1064 (HY000): SQL parser error ... syntax error near ' 中文别名'
```

## Version status
- v3.0.11 (Cloud): reproduces
- main / 4.0-dev (commit 0bfda60): reproduces