Investigate RPC-style abstraction for systems

[acmcarther]

Instead of embedding an "ordained" scripting language, instead provide an RPC style interface that external executables can "subscribe" to. It will require:

• An rpc for registering a service
• A harness for rpc systems in Rust (that locks the resources while the script executes)
• An rpc for calling the service
• A data serialization protocol for sending system state to the services

Suggesting:

• Only support standard objects and pub-sub (by extracting the events eagerly)
• Use protobuf or cap'n'proto for serialization and rpc
• Migrate an example service to use this framework

Please provide benchmarks for a no-op system in a language of choice and an example system of similar scope to the average system.

[acmcarther]

Work update on this before I forget for all of time.

I did some experimentation with capnproto and found the existing library made accessing and working with data too difficult. It adds a huge amount of boilerplate to all operations involving protos. In our case, that means almost all operations.

I haven't yet discounted capnproto, but I'm going to do more investigation with normal protobufs and the rust grpc implementation