Supports user params for scripts execution

Refer to https://docs.greptime.com/user-guide/python-coprocessor/io#input

For example, a script like:
```python
@coprocessor(returns=['value'])
def add(**params) -> vector[i64]:
a = params['a']
b = params['b']
return int(a) + int(b)
```

We can call this coprocessor with arguments `a` and `b`:

```
curl -XPOST \
"http://localhost:4000/v1/run-script?name=add&db=public&a=42&b=99"
```

The query parameters except `db` and `name` are collected into `params` for the coprocessor.

The dashboard can support these user input parameters for scripts.