Validate duplicate path of routes

[iudeen]

I have originally raised a PR in FastAPI for this: tiangolo/fastapi#5595

The PR aims to throw an error when two routes (functions) have same path defined.

I am starting to feel this would be a nice to have check on Starlette as we head towards 1.0.

Other frameworks like Flask have such a check as well.

Let me know your thoughts. I am happy to raise a PR if you agree to this.

[Kludex]

I don't think it's necessary.

[Kludex]

But... If the implementation is simple enough, maybe...