TO_IP

Converts an input string to an IP value.The input can be a single- or multi-valued field or an expression.Example:
```esql
ROW str1 = "1.1.1.1", str2 = "foo"
| EVAL ip1 = TO_IP(str1), ip2 = TO_IP(str2)
| WHERE CIDR_MATCH(ip1, "1.0.0.0/8")
```

Note that in the example above the last conversion of the string isn’t
possible. When this happens, the result is a null value. In this case a
Warning header is added to the response. The header will provide information
on the source of the failure:"Line 1:68: evaluation of [TO_IP(str2)] failed, treating result as null. Only first 20 failures recorded."A following header will contain the failure reason and the offending value:"java.lang.IllegalArgumentException: 'foo' is not an IP string literal."