Allow per-target IP protocol setting (IPv4 / IPv6) when resolving hostnames

[adrianmace]

I would like to be able to define the same target hostname twice, but have one resolve to IPv4 (A) while the other resolves to IPv6 (AAAA).

The use case is that I want to monitor the same destination but identify when latency for IPv6 changes compared to the IPv4 baseline.

Example Config:

receivers:
  icmpcheck:
    collection_interval: 10s
    targets:
      - target: www.amazon.de
        protocol: ipv4
        ping_count: 4
        ping_timeout: 5s
      - target: www.amazon.de
        protocol: ipv6
        ping_count: 4
        ping_timeout: 5s
     - target: 2001:db8::
     - target: 203.0.113.1