[Idea] - Federation of function executions

[jfaldanam]

Proposal: Allow eidos to publitize functions available in other instances of eidos, allowing each instance of eidos to own a subset of all different functions, while forwarding the execution in a way that all functions are available in all instances.

This allows the following:

• Have different instances with different hardware, allowing each type of instance to scale independently. For example, GPU-accelerated instances for deep learning related functions.
• Allow custom instances of eidos with different requirements of installed packages.
• Allow each team to maintain their own set of functions without depending on the main branch of eidos.

Concerns:

• An external coordinator is required to allow auto-discovery of instances. The alternative is to explicitly tell each instance which other instances it can connect to.