Implemented in this PR
- New base dialog for anything needing to work with the controller. This is important since going from SQL -> Controller we "should" have the right permissions but aren't guaranteed
- Support for Mount HDFS via a dialog. Includes basic polling for success/failure, but have to give up after 2.5min as mounting could take hours. By then it's assumed to be successful since server-side has 2min timeout built in.
Not implemented in this PR
- Script as Notebook button. This should convert the inputs to a set of cells in a notebook so users can run things themselves
- Updates based on PM / UX reviews. I think we'll need a round of feedback before completing this work.