The denylist kept the PURL namespace, but the Debian and RPM handlers
build pkg:deb/{name} and pkg:rpm/{name} without a vendor, while Alpine
and Arch build pkg:apk/alpine/{name} and pkg:alpm/arch/{name} with one.
So standard entries such as pkg:deb/debian/curl@... or
pkg:rpm/fedora/curl@..., and pkg:apk/busybox@... or pkg:alpm/glibc@...,
never matched. Drop the namespace of distro types on both sides, as
retention and the inventory already do, using packageurl's list of
those types.
Debian and RPM handlers read versions from filenames, which leave out
the epoch, so an entry such as pkg:deb/foo@1:2.3-1 never matched
foo_2.3-1_amd64.deb. An entry with an epoch now also covers the
version without it.
With purl v0.2.1, FullName returns a Swift package as its registry
identity, scope.name. The mirror splits namespace/name again to find
the scope or the source repository, so HandlerPackage keeps that form,
as mirrorTarget did before the two mappings were shared.
packageurl.HandlerPackage returns the ecosystem and name the handlers store
a package URL under. The mirror and the inventory both use it, which
settles where they disagreed: distribution namespaces of apk, alpm, bsd,
deb and rpm are dropped, PyPI and NuGet names use purl's comparison form,
and Maven names are group:artifact as the handler stores them, where the
mirror used group/artifact.
