[7.x] Convert processor supports validation of IPv4/IPv6 addresses (#69989)

[danhermann]

Adds a new type to the convert processor that validates IPv4/IPv6 addresses. Useful for guaranteeing that a particular field value can be mapped to an Elasticsearch ip field type. This is similar to the Beats processor functionality (described here) in which "the convert processor supports a psuedo-type for IPs. It doesn't really change the data type, but it will fail the "conversion" if the value is not an IP."

E.g.:

PUT _ingest/pipeline/ip_convert
{
  "processors": [
    {
      "convert": {
        "field": "source",
        "target_field": "source_ip",
        "type": "ip",
        "ignore_failure": true
      }
    }
  ]
}

# does not populate source_ip because invalid IP
POST /my-ip-test/_doc?pipeline=ip_convert
{
    "source" : "not_a_valid_ip"
}

# results in the following document (does not fail ingest pipeline because ignore_failure is set to true):
{
    "source" : "not_a_valid_ip"
}

# does populate source_ip because valid IP
POST /my-ip-test/_doc?pipeline=ip_convert
{
    "source" : "192.168.1.2"
}

# results in the following document (note that source_ip is still a string value):
{
    "source" : "192.168.1.2",
    "source_ip" : "192.168.1.2"
}

Resolves #36145

Backport of #69989

[elasticmachine]

Pinging @elastic/es-core-features (Team:Core/Features)

[danhermann]

@elasticmachine update branch