Refactor server codegen for restJson1 (#786)

* Refactor server restJson1 and allow generation of HTTP request
/ response tests

* Remove useless logging and only generate server specific tests

* Fix simple.smithy model and add tests for deserialization of URI and
method

* Don't double quote strings and just use the dq() method

Co-authored-by: Russell Cohen <russell.r.cohen@gmail.com>