Dots in query parameter names converted to underscores

seems to have a test failure

Did not test or review.

Thanks to those who have worked on this. The test fail is in a test introduced in this MR and appears to be worth researching and fixing.

I updated to issue summary based on my review of this issue and the related symfony issue.

Given how fragile the reimplemention of parse_str could possibly be, what are the thoughts on introducing an additional dependency like league/uri-query-parser or league/uri-components to handle it?

Since they probably have more test coverages and well-tested.

We could also try using something along the lines of https://www.php.net/manual/en/function.parse-str.php#126789 as a base as well.