[RM-18169] remotes: add a helper to write a sources list file from contents
[RM-18169] remotes: add a helper to write a sources list file from contents

Signed-off-by: Alfredo Deza <3f4d00ffa77e6441ab2d23c25a618925d2383b02@redhat.com>

ceph/ceph-deploy,ceph/ceph-deploy