Bbox support when converting

[felix-schott]

This PR adds support for bbox data when converting between formats:

geojson -> geoparquet

• When running gpq convert input.geojson output.parquet, bbox information present in the geojson data (top level "bbox" field as per the geojson spec) gets respected and put in a geoparquet bbox column (with the correct covering metadata written to the parquet header)
• Additionally, this PR introduces a parameter --add-bbox to gpq convert which results in a bbox column being added to the resulting parquet file even if not already present in the input data

geoparquet -> geojson

• When converting from geoparquet to geojson, the result geojson features will have a correctly populated bbox field (if present in the input parquet file)

Note: this PR depends on #264 which should be merged first (really this should probably be a PR to merge into 100_extract rather than main - the comparison between main and this branch will include all changes of #264 until #264 has been merged). As said before - I'm very happy to try and split this all up into smaller PRs if that makes things easier. These PRs are just the outcome of me tackling some issues without putting too much thought into splitting the work into digestable PRs.

Cheers
Felix