Redmine#5342: add Debian and Red Hat addupdate package fixes

see https://cfengine.com/dev/issues/5342 https://cfengine.com/dev/issues/5245 https://cfengine.com/dev/issues/2986

DO NOT MERGE YET

Summary:

* add `default_arch` for Red Hat and Debian package promises
* in `cfe_package_ensure`, treat the `yum_rpm` additive case specially, passing a package version that, to Yum, will not trigger installing e.g. `x-y-z` when package `x` is requested.  This requires the change in https://github.com/cfengine/core/pull/1625 that is broken (`ComparePackageVersionsInternal` needs to allow regex versions), so don't merge yet!