add size to backup-stats

interface/web/mail/backup_stats.php

interface/web/mail/lib/lang/ar_backup_stats_list.lng

interface/web/mail/lib/lang/bg_backup_stats_list.lng

interface/web/mail/lib/lang/br_backup_stats_list.lng

interface/web/mail/lib/lang/cz_backup_stats_list.lng

interface/web/mail/lib/lang/de_backup_stats_list.lng

interface/web/mail/lib/lang/el_backup_stats_list.lng

interface/web/mail/lib/lang/en_backup_stats_list.lng

interface/web/mail/lib/lang/es_backup_stats_list.lng

interface/web/mail/lib/lang/fi_backup_stats_list.lng

interface/web/mail/lib/lang/fr_backup_stats_list.lng

interface/web/mail/lib/lang/hr_backup_stats_list.lng

interface/web/mail/lib/lang/hu_backup_stats_list.lng

interface/web/mail/lib/lang/id_backup_stats_list.lng

interface/web/mail/lib/lang/it_backup_stats_list.lng

interface/web/mail/lib/lang/ja_backup_stats_list.lng

interface/web/mail/lib/lang/nl_backup_stats_list.lng

interface/web/mail/lib/lang/pl_backup_stats_list.lng

interface/web/mail/lib/lang/pt_backup_stats_list.lng

interface/web/mail/lib/lang/ro_backup_stats_list.lng