Provide access to the remote IP address in a handler #671

Problem statement

Currently, I see no way to get the remote IP address inside the handler, which may be necessary for logging, rate-limiting, login-control and so on.

Proposed solution

Cot could provide a remote_addr: IpAddr inside as a handler argument.

Alternatives considered

No response

Drawbacks

No response

Additional context

I tried to workaround this problem myself by writing my own middleware, but I could not find an explanation on how to do so nor an answer to the question whether making own middleware is an intended use of Cots' API.