Add support for query params in in_http input plugin

[omerlh]

Check CONTRIBUTING guideline first and here is the list to help us investigate the problem.

Is your feature request related to a problem? Please describe.

I am using fluentd to collect CSP violation report, I would like to add query params, like the website version to help us quickly spot issues related to a release.

Describe the solution you'd like

Add a property like add_query_params, that when set will parse the query params and add them to the record.

Describe alternatives you've considered

Passing it using a path and parsing the path with regex

Additional context

I'm willing to open a PR if the solution is acceptable

[repeatedly]

LGTM. Patches are welcome 👍

[omerlh]

Awesome! Opened a PR to add it...