vcl PDF export: fix re-exporting PDF images with page-level rotation
PDF images are effectively 1 page PDF documents. The page object may
have a /Rotate key, which was simply ignored before. We turn page
objects into form XObjects on PDF export, such rotation can be expressed
with a /Matrix key.
Add support for the 90 degrees rotation case, this can be generalized
later if wanted.
Change-Id: I55a4f63e0b986637ccdeba0b783f1db9a85c4d93
Reviewed-on: https://gerrit.libreoffice.org/82154
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins