cpp: bioformats: Correct Modulo default state

Initialise all members to match the Java implementation.
Align the size_type with the labels vector.
cpp: showinf: Improve dimension and resolution display
cpp: bioformats: Add getModelVersion to MetadataTools
cpp: bioformats: Add skeleton XMLTools
cpp: ome-xml: OMEXMLMetadataRoot uses virtual inheritance for MetadataRoot interface
cpp: bioformats: Add additional MetadataTools methods