Replicate Bio-Formats Importer dialog as an ImageJ2 command

When opening an image (either via File > Open or at least File > Import > Image), we want to show a dialog similar to the one shown by the Bio-Formats Importer. Some of the options there are made obsolete by SCIFIO, but many are still relevant. Part of addressing this issue is addressing exactly which are which.

Start by examining the existing File > Open and File > Import > Image entry points and comparing their behavior with the Bio-Formats Importer dialog. Determine which dialog options remain relevant with SCIFIO; done means the applicable options are identified and the ImageJ2 command presents the corresponding dialog.

Written by the indexing model from the issue text.