Cleaner and faster dask backend for delta lake read

[raviranak]

Saw the panda conversion in delta read with Dask Backend, so made changes to work with to_pyarrow_dataset
https://github.com/raviranak/yummy-rdev

[ion-elgreco]

@raviranak if all you're doing is grabbing the filenames it's easier to do: DeltaTable().file_uris()