OpenXML Filter: font information has to be available on extraction

[Denis Konovalyenko]

The consolidated code type name can be fonts and every unique font name can be listed via , symbol. For instance, x-fonts:Font 1,Font 2,Font 3; can be observed on extraction.

Example documents can be found attached.

[Denis Konovalyenko]

A related pull request #735 and a follow-up pull request #736 were merged,