Add initial support for reading BinaryOnly OME-TIFF datasets (rebased onto develop)



This is the same as gh-1090 but rebased onto develop.

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This adjusts the type detection slightly so that .companion.ome files
are detected as OME-TIFF, not OME-XML (as this makes finding and reading
the corresponding OME-TIFF files much easier).  Selecting either a
BinaryOnly OME-TIFF file or the corresponding companion OME-XML file
should result in the entire dataset being read.

Fixes https://trac.openmicroscopy.org.uk/ome/ticket/11951.  Sample files were generated from gh-1015, and are in ```data_repo/from_skyking/ome-tiff/samples/binary-only```.