Implement minimal RateLimitingMiddleware (#41008)

* First RateLimiting commit

* More

* ctrl-s

* lil bit

* Small

* Check-in launchSettings.json files from Middleware (#40695)

* sln

* More

* More

* More

* Remove stuff

* rm

* Not SharedFx

* Feedback

* Internal+IVT

* Feedback

* Feedback chunk 1

* Feedback chunk 2

* Small feedback

* Fix extension methods

* Small fix

* Func

* Config status code

* Feedback, add servicecollection extension

* Update API

* Some feedback

* Lil more feedback

* Partially fix test

* Fix/Add tests

* Add another test