[core] Support parsing row type json without field id

[Zouxxyy]

Purpose

As part of #4471, in order to support variant shredding, we need a way to indicate which fields require shredding. To reuse the code, we utilize the existing RowType JSON parser.

E.g. If we want to shred field v with age int and city string, we can create table like this:

CREATE TABLE T (v VARIANT)
TBLPROPERTIES (
'fields.v.shredding-schema' = '{"type":"ROW","fields":[{"name":"age","type":"INT"},{"name":"city","type":"STRING"}]}'
)

To reduce user conf, support parsing row type json without field id

Tests

API and Format

Documentation

[JingsongLi]

+1