Combine all RPC modules in one

Summary

In the current code base, the RPC methods are split into various RPC modules that must loaded at run-time. This is sub-optimal and creates confusion with the templated RPC framework. Moreover, once #124 (closed) will be implemented, most, if not all, modules will have to be loaded.

In order to simplify the maintainance and usage, all RPC modules can be mreged into one while keeping the seperation into sementically correct namespaces.

What is the expected correct behavior?

Only one RPC module should be provided and used.