Additional tools for working with IBE, including SIA access

PR includes tools for listing the valid / available data sets, missions, tables and a tool for querying the SIA component of IBE (which is the only programmatic way to get image access, as far as I can tell)
Was that really true for all of them?  If so, I think the dict is still useful, but perhaps reversed.  I do like navigating to the docs with `webbrowser.open` though.  Can you work on that?