[BUG] Selecting struct column drops field names

[devavret]

After reading a dataframe from this parquet file and selecting the list of structs column "value", cudf drops the field names of the struct.

In [1]: import cudf

In [2]: df = cudf.read_parquet("maptest.parquet")

In [3]: df
Out[3]: 
                                               value
0  [{'key': {'first': 'John', 'middle': 'Y.', 'la...

In [4]: df["value"]
Out[4]: 
0    [{'0': {'0': 'John', '1': 'Y.', '2': 'Doe'}, '...
Name: value, dtype: list

This is unlike pandas' behaviour which retains the field names

In [5]: df.to_pandas()["value"]
Out[5]: 
0    [{'key': {'first': 'John', 'middle': 'Y.', 'la...
Name: value, dtype: object