Remove MountPolicy object from objectstore schema
The Retrieve/Archive/Repack requests in the objectstore contain the entire mount policy information. This is filled at queueing time and is useless since we just use the name and get the up to date mount policy from the catalogue. It should just contain a string of the mount policy, since it is the only field used. It causes confusion when dumping the object, since it prints all the mount policy fields, when only the name matters.
Not really high priority I think.