With dnf5 there is a successor for dnf but there will also
be a transition period where there will be both, the former
dnf and the new dnf5 available. For a clear distinction
between the two we got the recommendation from the RedHat
team to support both in different namespaces. This commit
now implements a backward compatible change for kiwi which
includes the following modifications:
* XSL stylesheet for automatic schema transformation from
<packagemanager>dnf</packagemanager> to
<packagemanager>dnf4</packagemanager>
* Code copy of dnf API interface from
PackageManagerDnf -> PackageManagerDnf4
RepositoryDnf -> RepositoryDnf4
* Deprecation of former Dnf API interface
The code change here will force developers to adapt
their code if they used RepositoryDnf / PackageManagerDnf
classes in their python code. After this change developers
will be dropped into a raise condition which exits kiwi
at the time of the call. Related to Issue #2300
and Issue #2262
