Fix Insert 3D Model file dialog's "All supported formats" filter

It seems on some system the file dialog does not like spaces
between the formats.

(cherry picked from commit fd63ba45742e0886f15f907c03025b9dcc84d8ab)

Conflicts:
	sd/source/ui/func/fuinsert.cxx

Change-Id: Ifa69f4f210061209f7f0aa9223417d06b06b577a
Reviewed-on: https://gerrit.libreoffice.org/11016
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>