Files containing deeply nested lists fail to be transformed to CSV and XLSX

[tillywoodfield]

This is currently affecting all files which use the Location geometry/type of Polygon, for example:

{
    "type": "Polygon",
    "coordinates": [
        [
            [100.0, 0.0],
            [101.0, 0.0],
            [101.0, 1.0],
            [100.0, 1.0],
            [100.0, 0.0]
        ]
    ]
}

These files will fail to be transformed to CSV and XLSX, so are available in JSON format from the datastore.

I think this is caused by the bug described in OpenDataServices/flatten-tool#477.

To solve this there are two options:

1. Solve the bug in flatten-tool
2. Switch to another library for transformation, e.g. flatterer

[duncandewhurst]

I think this can be solved by setting the --convert-wkt flag in Flatten Tool.