Error aliasing on double unnest on List[Struct]

### Describe the bug

Using a datafusion table with a column (`col`) of type `List[struct[]]`. Calling
```sql
SELECT unnest(unnest(col)) as col_name
FROM tbl
```

Results in the error

```shell
Internal error: unnest on struct can only be applied at the root level of select expression.
This was likely caused by a bug in DataFusion's code and we would welcome that you file an bug report in our issue tracker
```

### To Reproduce

Context
```
sql> describe test_tbl
+-------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------+
| column_name | data_type | is_nullable |
+-------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------+
| id | Utf8 | YES |
| labels | List(Field { name: "item", data_type: Struct([Field { name: "name", data_type: Utf8, nullable: true, dict_id: 0, dict_is_ordered: false, metadata: {} }]), nullable: true, dict_id: 0, dict_is_ordered: false, metadata: {} }) | YES |
+-------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-------------+
```
Without Alias
```
sql> select unnest(unnest(labels)) from test_tbl limit 3
+-----------------------------------------+
| unnest(unnest(test_tbl.labels)).name |
+-----------------------------------------+
| kind/bug |
| kind/enhancement |
| kind/enhancement |
+-----------------------------------------+
```

With Alias
```
sql> select unnest(unnest(labels)) as a from test_tbl limit 3
Status { code: Internal, message: "Internal error: unnest on struct can only be applied at the root level of select expression.\nThis was likely caused by a bug in DataFusion's code and we would welcome that you file an bug report in our issue tracker", metadata: MetadataMap { headers: {"content-type": "application/grpc", "date": "Mon, 26 Aug 2024 00:25:51 GMT", "content-length": "0"} }, source: None }
```

### Expected behavior

```
sql> select unnest(unnest(labels)) as an_alias from test_tbl limit 3
+-----------------------------------------+
| an_alias.name |
+-----------------------------------------+
| kind/bug |
| kind/enhancement |
| kind/enhancement |
+-----------------------------------------+
```

### Additional context

For outputs, using [spiceai](https://github.com/spiceai/spiceai/), specifically [spice sql](https://github.com/spiceai/spiceai/tree/trunk/bin/spice).

Start by reproducing the nested UNNEST query with and without the alias, using the spice sql context described in the issue. Trace the alias handling for UNNEST over List[Struct]; the fix is complete when the aliased query returns the expected struct field output instead of the internal error.

Written by the indexing model from the issue text.