[libhif] Implement support for install-langs
[libhif] Implement support for install-langs

tmp-user/rpm-ostree,giuseppe/rpm-ostree,giuseppe/rpm-ostree,giuseppe/rpm-ostree,tmp-user/rpm-ostree,mdshuai/rpm-ostree,mdshuai/rpm-ostree,mdshuai/rpm-ostree,tmp-user/rpm-ostree,mdshuai/rpm-ostree,giuseppe/rpm-ostree,tmp-user/rpm-ostree