#2 compability with new LaTeX pdfmanagement

[U_Fischer]

in connection with the project "Tagged PDF" we are
extending the support for pdf related commands in the LaTeX kernel.

The new code is in part already in the kernel (in l3pdf and l3kernel)
and in part in a temporary testphase package pdfmanagement-testphase.

Most importantly: with the new code we want to replace a few primitives
which write to central dictionaries and resources in the pdf by a new
managed command to prevent clashes between packages and kernel code.
This means that packages which use one of \pdfinfo, \pdfcatalog,
\pdfpageattr, \pdfpagesattr or \pdfpageresources (and analog commands
of the other engines) are incompatible with the new pdfmanagement.

This affects storebox which uses \pdfpageresources when creating the resources of the xform.