Added table count and names after successful import fixing #1086

Since I couldn't know how were tables joined at "table_names" text column I've joined them just with spaces. I think in case of multiple tables they were overriden (see ```data_import.rb#278: self.update(table_names: new_table_name)```). @Kartones review this, please. I'm not sure about having pushed ``lib/assets/javascripts/cdb``` change.