Entry fallback translation

Without this isn't possible to translate the default "entry name"
Sounds good to me. Maybe we can do this in [Kaminari::ActiveRecordRelationMethods](https://github.com/amatsuda/kaminari/blob/507fb73b09475a0efbd99d0398bf4a3c9632ca18/lib/kaminari/models/active_record_relation_methods.rb#L12)?