* [PHP] - Add FormDataProcessor to handle nested ModelInterface data
* Generating samples
* Updates php-nextgen and psr-18
* Adds tests
* Some more tests
* One last test
* Updating files
* Fixing diff
* Test fix
* Updating samples
* [PHP] - Add range HTTP code support
* Adding response body to 200
* Fix diff; update php-nextgen sample
* Working on unit tests
* Removes dangling files
* Finalize tests
* Remove dangling files
* Add tests for no response body exception