Add optional transfer step to dataset DAG

[anayeaye]

What

Add an optional transfer option to dataset DAG that will copy files from veda-data-store-staging/ to the production bucket/ before starting file discovery and metadata generation. This will support SM2A programmatic use of the dataset DAG.

AC

• OPTIONAL transfer flag will cause files to be transferred from current prefix to production/ when provided and true

[smohiudd]

#259

[anayeaye]

Look at CSDA restore SM2A DAG which restores objects from glacier before triggering the processing pipeline