Summary

This PR solves the problem that existed in the scenario where the urls list contains mix of IPv4 and IPv6 addresses and the interface is config file set.
Until now, the plugin chooses the first available address for the given interface. In my case, it was IPv6 for Windows and IPv4 for Linux. Because of this, the plugin worked incorrectly with IPv4 addresses for Windows and IPv6 addresses for Linux.

Here is a list of the most important things done in this PR:

• Each URL now has its own httpClient (until now, one httpClient was used to handle all URLs).

• Each URL provided in the config and each address for the given interface in the config is parsed and checked to see if it is an IPv4 or IPv6 address.

  • I didn't find methods in the standard library (or in other dependencies) that would do this correctly and handle both url.URL and net.IPNet. That's why I added github.com/seancfoley/ipaddress-go lib. The topic of parsing addresses is complex enough that I didn't see the point in doing it myself. If any of the reviewers have an idea on how to do this better, I would be happy to hear it :)

• Each URL has a httpClient assigned that matches the address format (IPv4 or IPv6).

• Configuration checking and initializing defaults have been moved from Gather to Init.

  • This changes the behavior of the plugin slightly, which will now fail immediately if:
    • parsing the regular expression from h.ResponseStringMatch fails
    • at least one of the URLs provided in the config cannot be parsed
    • at least one of the URLs provided in the config is not of type http or https
    • another problem occurs while creating the httpClient for the URL

  (previously, these errors could occur in Gather, which did not cause the plugin to fail, but rather resulted in recurring errors in the logs)

Thanks to this PR, the http_response plugin tests for Windows are re-enabled.

Checklist

• No AI generated code was used in this PR

Related issues

resolves #8451