Properly fix serialization of raw identifiers in minified serialization

The problem here was that our custom implementation of minified serialization is missing the unraw transformation applied by serde's proc_macro meaning that the raw identifier r#type was serialized using the key r#type instead of type. This change adds a unit test catching this and properly fixes this using a bit of compile time function evaluation gymnastics to ensure that the r# prefix is stripped at compile time instead of during runtime to avoid any performance impact as we cannot just process the value returned by stringify as the original proc_macro can.