[Python/C++] Empty column selection no longer restores index

The index of a dataframe is no longer reconstructed when using empty column selection. This is a regression to 0.12.1 and probably only happens for pd.RangeIndex

```python

import pandas as pd
import pyarrow as pa
import pyarrow.parquet as pq
from kartothek.serialization import ParquetSerializer
from storefact import get_store_from_url
print(pa.__version__)
df = pd.DataFrame(
{"a": [1, 2]}
)
print(df.index)

table = pa.Table.from_pandas(df)
buf = pa.BufferOutputStream()
pq.write_table(table, buf)
reader = pa.BufferReader(buf.getvalue().to_pybytes())
table_restored = pq.read_pandas(reader, columns=[])
df_restored = table_restored.to_pandas()
print(len(df_restored))
```

**Reporter**: [Florian Jetter](https://issues.apache.org/jira/browse/ARROW-5139) / @fjetter
#### Related issues:
- [[Python] RangeIndex serialization change implications](https://github.com/apache/arrow/issues/21880) (is related to)

_{**Note**: *This issue was originally created as [ARROW-5139](https://issues.apache.org/jira/browse/ARROW-5139). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}

Start by running the supplied Python reproduction and inspect the path triggered by pq.read_pandas(reader, columns=[]), focusing on how RangeIndex metadata is restored after empty-column selection. Done means the restored dataframe retains the original RangeIndex and row count without affecting ordinary column reads.

Written by the indexing model from the issue text.