Public WampResult type wraps private Error type

[elast0ny]

https://github.com/ohyo-io/wampire/blob/de5aa3b46789edef767440ff97885f5b3271271e/src/lib.rs#L17

The WampResult type which is returned by many public facing APIs wraps the private wampire::error::Error type.

This prevents callers from implementing From(wampire::error::Error) for their custom error types.