Bug 24756: Fix failing tests by removing temporary filenames

Bug 24756: Fix failing tests by removing temporary filenames

In order to resolve the random failure, that might be caused by reusing
filenames in File::Temp and caching xslt code, this patch replaces the
temporary file by using the code parameter.

Note: Since XSLT uses a digest based on the passed code fragment, we will
exclude collisions here.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>