Force sum/average to be calculated as a float.
As noted in #8221
> run SELECT AVG(CAST (Score as int)) FROM S3Object on
```
Name,Score
alice,80
bob,81
```
> AWS S3 gives 80.5 and MinIO gives 80.
This also makes overflows much more unlikely.
- New parser written from scratch, allows easier and complete parsing
of the full S3 Select SQL syntax. Parser definition is directly
provided by the AST defined for the SQL grammar.
- Bring support to parse and interpret SQL involving JSON path
expressions; evaluation of JSON path expressions will be
subsequently added.
- Bring automatic type inference and conversion for untyped
values (e.g. CSV data).
