BitmapEx and tools::Time are both value objects, no need to use
std::unique_ptr for them

Change-Id: Ibeed7da46ccc8fd3cd3301d364ae33c33c0114bb
Reviewed-on: https://gerrit.libreoffice.org/56198
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>