Add property to GeoIp processor continent_code.

[jhaos]

Description

Hi, I'm currently using in my environment for ingestion filebeat>logstash>Elasticsearch, in order to reduce the resources we are going to take out Logstash and start using Filebeat instead directly to ingest the data to Elasticsearch.

I'm using the field continent_code and made several dashboards since Logstash allows it, check https://www.elastic.co/guide/en/logstash/current/plugins-filters-geoip.html, but checking the documentation to use an Elasticsearch processor there is no continent_code field, check https://www.elastic.co/guide/en/elasticsearch/reference/current/geoip-processor.html, but continent_name which I'm are not using in the template nor in the already ingested alerts.

Asking in the community channel I couldn't find any alternatives and one user suggested opening a feature request https://elasticstack.slack.com/archives/CNEDGGJQ3/p1649742148197329

The alternative would be to rename the field property in the template or delete it, but in any case, I will have to reindex all the data to adapt to the new fields and modify the dashboards that currently are using continent_code, and change to continent_name which is a tough task when several environments are involved with this kind of dashboards.

I would be appreciated, if possible, having this feature as soon as you can add it if you decide to.

Thanks in advance.

[elasticmachine]

Pinging @elastic/es-data-management (Team:Data Management)