Fixed `Netzke::Basepack::DataAdapters::ActiveRecordAdapter#get_records` to handle polymorphic associations
Fixed `Netzke::Basepack::DataAdapters::ActiveRecordAdapter#get_records` to select all fields if no one has pre-selected the required one manually, e.g. by calling select([:one_field_used_in_the_grid, :another_field_used_in_the_grid]) or an adequate scope