Generate request objects

[Whathecode]

Currently, for each endpoint, a request object and JSON schema needs to be created. Albeit useful, this is boilerplate code.

I've recently started using kotlinx.rpc, which does something very similar (supports RPC calls on simple Kotlin interfaces by generating intermediate request objects). We should have a look what compiler plugin they use under the hood to do this. Or, possibly we can use their implementation to generate our request objects. Apparently they provide access to the "service descriptors" they generate.