Add ability to store monitoring data in VictoriaMetrics

[valyala]

VictoriaMetrics supports data ingestion via Influx line protocol (see these docs), while it usually needs lower amounts of compute resources (CPU, RAM, disk space, disk IO) compared to InfluxDB (see these benchmarks and these case studies). So it would be great if Pi-Hole-Monitoring could use VictoriaMetrics as monitoring backend.