Add GeoPandasSerializer

[rdmolony]

Hi there, I've adapted PandasSerializer to work with geopandas at rdmolony/prefect-geopandas-serializer but only for parquet. Is there any interest in adding this to prefect.engine.serializers?

It needs to be better tested and perhaps to support more filetypes than parquet which is still experimental in geopandas (16/08/2021) - the default geopandas.GeoDataFrame.to_file serializes to a shapefile which is a directory of files and not a single file and so didn't gel nicely