This issue is a collection of bug fixes for the few bugs that where discovered from the FastAPI alpha release.

• Patch FastAPI get_request_handler to extract request body data (fixes the infinite loop when doing form posts in FastAPI) FastAPI Integration - TypeError: 'coroutine' object is not callable #1514
• Fix patching exception handlers in _sentry_patched_exception_handler(fixes the error on non existent routes) FastAPI Integration - TypeError: 'coroutine' object is not callable #1514
• Made Starlette middleware patching idempotent to prevent patching functions twice (no GitHub issue for that)
• Patch request_response in Starlette to extract request body data (fixes the infinite loop when doing form posts in Starlette) FastAPI Integration - TypeError: 'coroutine' object is not callable #1514
• Starlette has async and sync "views" (or route handlers) in the sync ones it is not easily possible to get the request body data (because those functions are async) so we just get the cookies form the sync route handlers and not the body data. (no GitHub issue for that)