🐛 fix parse gzipped body

[faceair]

Now when we use filber.Ctx.BodyParser to deserialize JSON, it uses filber.Ctx.fasthttp.Request.Body method internally to take the raw body data, which works fine in most cases.

But when the request body is gzip-compressed, filber.Ctx.fasthttp.Request.Body takes the compressed data and there is no way to deserialize it directly.

So in this PR I changed the method inside filber.Ctx.BodyParser that takes the request body to filber.Ctx.Body method, which automatically detects the encoding of the request body and decompresses it itself. I have also added test cases for compression requests.

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[ReneWerner87]

Thanks for the pull request, understand the code also, but not quite the description, can you adjust this again a bit, so that everyone knows what should be achieved with the pull request, if someone goes through the link in the release on the pull request

[faceair]

Thanks to review, I have added more complete description information.

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