Mpservice

- Minor improvement to `mpservice.multiprocessing.server_process`.
- Upgraded `uvicorn` to 0.30.0; revised `mpservice._http` accordingly.

- Refactored and enhanced `mpservice.multiprocessing.server_process`.

- `mpservice.multiprocessing.server_process.ServerProcess` enhancement: if a proxy function raises exception in the server process, a `mpservice.multiprocessing.remote_exception.RemoteException` is returned to the request and then raised to the user, hence the user (outside of the server process) gets more useful traceback info.
- `mpservice.multiprocessing.server_process` is heavily refactored for enhancements and simplifications.

- `mpservice.mpserver.Worker` gets new method `stream` for some special use cases.

- `mpservice.mpserver.Worker.__init__` loses parameter `batch_size_log_cadence` and gets new parameter `cpu_affinity`,
which also becomes an attribute of the worker instance.

- Removed some deprecated code.
- `mpservice.mpserver.Worker` gets new method `cleanup`.