When loading QTAIM files, switch to the navigate tool.

Fixes PR#687.
Consistent with normal Open.. or Import.. behavior.
Also switched menu items to include "..." to indicate
they open new files, consistent with UI elsewhere.

Change-Id: I8eb0f87155748a370bd842cdfe1b049a504f343c
Merge topic 'ENH_qtaim-navigate-tool' into master

79b241a1 When loading QTAIM files, switch to the navigate tool.