Full data dump export

[cutepig]

Closes #231

Adds a new dataset responses_full.json, which features all responses filtered and mapped as follows:

• Removed the fields response_id, app_version and abuse_score Map postal codes according to low_population_postal_codes.json
• Remove the responses that have a postal_code we can’t find in postalcode_city_mappings.json
• Reset minutes, seconds and microseconds to zero in timestamp
• Set age_group to either under50 or over50 comparing the incoming age_group to < 50
• Set gender to be either male or female, other values coalesce to male

Test locally with the CLI tool:

npm run --silent open-data-cli dump responses_full.json > /tmp/responses_full.json

See an online example at https://data.dev.oiretutka.fi/responses_full.json