Fix warnings display in CSV import result
[#50] Remove archive and verified fields

Requires removing data from the DB as well
[#52] Extract standard version on archiver and display it

If not present or value is not allowed, 'n/a' is set. Allowed versions
can be defined via the `iati.standard_versions` config option. Default are
1.01 1.02 1.03 1.04 2.01
[#55] Change header label
[#56] Remove link to CSV download from dataset page and listings
[#54] Add notice about size limit