Starlette is not typed to an ASGIApplication → Type check warning in PyCharm with FastAPI and Uvicorn

[eshfield]

The problem:
PyCharm gives ugly type check warning when I try to run FastAPI app with uvicorn programmatically passing to uvicorn.run() the application instance of the FastAPI class.

I have created the issue in the FastAPI repository and they say the problem is since FastAPI extends from Starlette the issue is that Starlette is not typed to an ASGIApplication, i.e. fix must be done in the Starlette code:
fastapi/fastapi#3927

Steps to reproduce:
Copy and paste to PyCharm the example code from the official FastAPI documentation Debugging → Call uvicorn
PyCharm will highlight the app argument at the last line uvicorn.run(app, host="0.0.0.0", port=8000) with warning:
Expected type 'Union[Type[ASGI2Protocol], (Union[HTTPScope, WebSocketScope, LifespanScope], () -> Awaitable[Union[HTTPRequestEvent, HTTPDisconnectEvent, WebSocketConnectEvent, WebSocketReceiveEvent, WebSocketDisconnectEvent, LifespanStartupEvent, LifespanShutdownEvent]], (Union[HTTPResponseStartEvent, HTTPResponseBodyEvent, HTTPServerPushEvent, HTTPDisconnectEvent, WebSocketAcceptEvent, WebSocketSendEvent, WebSocketResponseStartEvent, WebSocketResponseBodyEvent, WebSocketCloseEvent, LifespanStartupCompleteEvent, LifespanStartupFailedEvent, LifespanShutdownCompleteEvent, LifespanShutdownFailedEvent]) -> Awaitable[None]) -> Awaitable[None], str]', got 'FastAPI' instead

[Kludex]

Duplicated #1249

PR is welcome. :)