Support for `application/x-www-form-urlencoded`

It seems like this implementation only currently supports content-type `applciation/json`. Is it possible to use `application/x-www-form-urlencoded` by any chance?

No file, test, or entry point is named. Start by locating the current handling for application/json and trace how request content types are parsed and validated. Done means application/x-www-form-urlencoded requests are supported with documented behavior and coverage for the new content type.

Written by the indexing model from the issue text.