Drop concatenated title of 'Add' dialog for details of entity
    
    As for now the 'Add' dialog title, which is initialized within
    details of the entity, contains translated concatenated texts,
    like:
        'Add ${other_entity} into ${entity} ${primary_key}',
    where 'other_entity' and 'entity' are also translatable texts.
    This construction is used via method 'show_add_dialog' of
    association_facet for the all 'Add' actions within details
    of entities.
    The concatenation leads to a bad quality translation and
    should be changed to an entire sentence.
    
    From now a mentioned title is taken from a spec and should be
    specified explicitly.
    
    Fixes: https://pagure.io/freeipa/issue/7712
    Fixes: https://pagure.io/freeipa/issue/7714
    Reviewed-By: Serhii Tsymbaliuk <stsymbal@redhat.com>