[Serve] Rewrite Ray.Serve From Scratch (#5562)

* Commit and format files

* address stylistic concerns

* Replcae "Usage" by "Example" in doc

* Rename srv to serve

* Add serve to CI process; Fix 3.5 compat

* Improve determine_tests_to_run.py

* Quick cosmetic for determien_tests

* Address comments

* Address comments

* Address comment

* Fix typos and grammar

Co-Authored-By: Edward Oakes <ed.nmi.oakes@gmail.com>

* Update python/ray/experimental/serve/global_state.py

Co-Authored-By: Edward Oakes <ed.nmi.oakes@gmail.com>

* Use __init__ for Query and WorkIntent class

* Remove dataclasses dependency

* Rename oid to object_id for clarity

* Rename produce->enqueue_request, consume->dequeue_request

* Address last round of comment

python/setup.py

@@ -68,6 +68,7 @@ extras = {
     ],
     "debug": ["psutil", "setproctitle", "py-spy"],
     "dashboard": ["psutil", "aiohttp"],
+    "serve": ["uvicorn", "pygments", "werkzeug"],
 }