file_size was designed for old template

[jackhannah95]

file_size was designed to aid in the creation of the 'List of Tables' section of ISD's Official and National Statistics publications (e.g. the table on page 25 of the 2019-11-12 HSMR publication).

Once ISD moves to its new website in March/April 2020, the 'List of Tables' section will be removed from the publication templates and this function will likely become somewhat redundant (it may still be useful until then however). Instructions will hopefully follow from the web team on how an adaptation of file_size could be used as part of the new website.