This PR enhances the messaging system with the new StaticType class. It allows sendBlocking() return values to be deserialized to the expected return type, simultaneously type-checking the return value. An example:

Currently, to call a remote method and get the return value you would do something like this:

List<Registration> registrations = (List<Registration>) sendBlocking("runtime", "getServiceList");

Assuming getServiceList() returned the expected list, this would work just fine thanks to the virtual class field embedded in the JSON. However, if this method changed to return a list of ServiceInterface or something, this would still succeed since casting can't check generics at runtime. It would only blow up upon accessing the list, with a ClassCastException, potentially several message hops away.

Now, one would do this:

List<Registration> registrations = sendBlocking("runtime", "getServiceList", new StaticType<>(){});

Note the lack of a cast and the new StaticType parameter. This "reifies" the expected return type, allowing it to be accessed at runtime. It is then accessed by CodecUtils when deserializing a message, informing the deserializer of the requested type. If the object is not of the expected return type (or an allowed alternative like a subclass), then the deserialization fails. This ensures we don't pass bad data around before crashing with a hard-to-debug ClassCastException

Fixes #1226

NOTE:
This does not work for return types with non-concrete generic parameters. For example:

List<T> registrations = sendBlocking("runtime", "getServiceList", new StaticType<>(){});

This will fail even if T is defined by a class or method generic parameter. This is because StaticType cannot reify non-concrete generic type parameters even if they are defined somewhere else.

I also do not know how wildcards will function with this. For example:

List<? extends Registration> registrations = sendBlocking("runtime", "getServiceList", new StaticType<>(){});

This may or may not fail, but if it does fail, it will do so during construction of the StaticType. More testing is needed for this.