[PackageKit] Move zypp cache from root to home partition. JB#62835

This reduces the root partition free space requirements substantially.
The cache location is created at runtime if it doesn't exist.

rpm/packagekit-zypp-override.conf

@@ -1,5 +1,5 @@
 [main]
-cachedir = /var/cache/pk-zypp-cache
+cachedir = /home/.pk-zypp-cache
 # Whether to consider using a .delta.rpm when downloading a package
 download.use_deltarpm = true
 # Whether to consider using a deltarpm even when rpm is local