Request body: re-init raw request's body after reading-for-decode

[rom8726]

Description

Hi! It seems to me very important to reinitialize the raw http request body (req.Raw.Body). The developer should be able to read the raw contents of the request body. This is necessary, for example, for logging raw requests or for the task of verifying the authenticity of a request, when a signature (arrives in the header) generated cryptographically based on the request body and secret key, and the signature must be verified in the request handler.

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