Support JSON lines with missing columns
Support JSON lines with missing columns.

Fix #7169.

The implemented test raised:
```
datasets.table.CastError: Couldn't cast
age: int64
to
{'age': Value(dtype='int32', id=None), 'name': Value(dtype='string', id=None)}
because column names don't match
```

Related to:
- #7160 
- #7162