Some properties in File->Properties->General Tab are not set for remote docs

This patch handles the case in which no meta information could be extracted from
the file, so CMIS properties are displayed instead, if it is a CMIS document.
Size and creation/modification dates are handled here.

Change-Id: I97f920172b15a76297d78a33ac3a07a8333ef8a6
Reviewed-on: https://gerrit.libreoffice.org/10511
Reviewed-by: Bosdonnat Cedric <cedric.bosdonnat@free.fr>
Tested-by: Bosdonnat Cedric <cedric.bosdonnat@free.fr>