Option to export all metrics to multiple Influxdb servers

As confirmed with support in current checkmk version you can only send metrics to one influxdb server. You can send some metrics to one influx server and other metrics to another, but you cannot send the same metrics to multiple influxdb connections.

Possible applications:
- increase reliability - if you use OSS influx version (without clustering) you can send to two or more servers or even separate sites to ensure nothing gets lost in case of server/site failure
- separate data per criticality or retention - have hot/cold influx nodes for current monitoring and archive data - influx loves fast storage, but it gets very expensive to keep older data
- if you use MSP version - export data to your clients, keeping copy to yourself; same case with different departments in your company

You CAN export metrics to multiple graphite servers, but you cannot choose which metrics go where. Also - carbon protocol is unreliable when dealing with larger sites/number of metrics.