Import of drawing canvas in docx documents

[Regina Henschel <rb.henschel@xxxxxxxxxxx>]

Hi all,

my patch https://gerrit.libreoffice.org/c/core/+/156629 is ready for 
review. Please have a look.

It has unit tests that show what is now possible compared to the import 
of the VML fallback.

I'm unsure about writing conventions, e.g. when start with lower or 
upper case. Please advise me.

Kind regards,
Regina