Replace utils/Makefile.SH with utils/Makefile.PL

Replace utils/Makefile.SH with utils/Makefile.PL

This shares all the existing deficiencies of utils/Makefile.SH, and
generates a byte-for-byte identical utils/Makefile, including boilerplate
that claims it was generated by utils/Makefile.SH

utils/Makefile remains as a file checked into the repository, and is not (yet)
deleted, because as-was only *nix platforms could run utils/Makefile.SH to
generate utils/Makefile. This messy state of affairs means that if you build
with static linking, the checked-out utils/Makefile is modified
('../miniperl' is replaced with '../perl')

The next commit will resolve just these bugs.

In turn, it seems that the pre-generated utils/Makefile is only used by
Win32, as VMS contains rules in descrip_mms.template to build the
utilities. Probably the next thing to unpick is the build on VMS, but it
seems better to reduce the size of the "problem" in both utils/Makefile.PL
and vms/descrip_mms.template by attempting to move the work from them to
the extension directories and ExtUtils::MakeMaker.