[Templates][Fixes #13641] Run rimraf before running the app to give it a...

[Templates][Fixes #13641] Run rimraf before running the app to give it a better chance of avoiding a failure

* Rimraf has reliability issues on windows.
* This change runs rimraf with a few retries before starting the app with `dotnet run` so that `npm run start` on the ReactDeveloperMiddleware has a better chance to succeed.