Being able to use a non-ephemeral ClientApp in the SuperNode

[relogu]

Describe the type of feature and its functionality.

For some FL settings, one may want to use some computing resources to execute a unique FL pipeline. As long as the ClientApp is ephemeral in the SuperNode, every message received/sent by the client requires loading the ClientApp almost from scratch with the overhead of loading libraries and, potentially, heavy client subprocesses that are usually very slow to load in Python. Possessing a static/non-ephemeral ClientApp would allow to avoid such overheads.

Describe step by step what files and adjustments are you planning to include.

I believe that inserting a flag the _start_client_internal function that allows to create and keep the ClientApp out of the scope of the main while loop instead of temporarily creating it in try-except clause could be sufficient.

Is there something else you want to add?

I can add more details if the description is not detailed ennough.enough