Use st.file_uploader() widget as an option for loading files into the datafile unifier

[andrew-weisman]

If we implemented this, then on NIDAP users would only ever need a single link (to the app, and not to the input dataset). I tested a prototype and it works in published dashboards with no upper limits, e.g., I tested upload of a 2.2 GB file and it worked just fine.