Display authorization settings to UIS owner?

[hjoliver]

See also #259

Authorization config requires valid Python syntax as well as the correct data structure and item names and values. Any error results in the user config being silently ignored. (Accessing user permissions are logged, if logging with sufficient verbosity, to the hub console, but that ain't much use).

We should probably display a table of authorization settings in the UI, for the authenticated UIS owner to see, and encourage users to double check that after making any changes.