Support more table stores (i.e. for parquet files or apache arrow dataframes in-memory)

[adzcai]

Currently the backend supports either a database backend or a blob backend. It would be nice to enable materializing other types of files, notably Parquet files, as well as blobs. This might enable pydiverse.pipedag to also be used in more lightweight pipelines that don't require the overhead of a SQL backend and can work directly with disk files instead.

[windiana42]

In deed it is planned to create table backends that either store tables in parquet files on disk or blob store (i.e. S3) or in memory as apache arrow dataframes.
=> I will rename the issue to reflect the aspect that this request mostly touches extention of more table stores.