Remove or finish implementation of cta-admin commands which are not functional

The following commands are not working at the moment:

cta-admin schedulinginfo ls
cta-admin listpendingarchives -x
cta-admin listpendingarchives
cta-admin listpendingretrieves -x
cta-admin listpendingretrieves
  

There is a code that suggest they were operational in the past.