Create middleware binding sample

Cleanup and bring the sample in https://github.com/fabiocav/MiddlewareBinding to the repo.

Start by reviewing the existing sample in https://github.com/fabiocav/MiddlewareBinding and compare it with the azure-functions-dotnet-worker repository structure. Identify the expected sample location and any project or documentation conventions before bringing it into the repo. Done means the sample is cleaned up and included in the repository, but the issue does not specify tests or a target path.

Written by the indexing model from the issue text.