Allow the use of a struct without having a corresponding Java class

[texasspurstar]

Currently StaticStruct and DynamicStruct require a dev to implement any new struct as Java class.

But what about situations where the dev does not know the struct object at development time?

This is exactly what we need: to support all structs in our software, but without knowing what these structs will be beforehand.

[aceppaluni]

I can take this on