Fix download paths `estios/estios/uk/data` to `estios/uk/data`

Currently the following data files default to `estios/estios/uk/data` rather than `estios/uk/data`

- obs05jul2021.xls
- pop.csv
- nasu1719pr.xlsx                           
- ukmidyearestimates2017finalversion.xls
- ukpopestimatesmid2020on2021geography.xls
- oecd_long_term_forcasts.csv 
- oecd_ppp_currency_converter.csv