Better support for dynamic numbers of inputs

[josephmckinsey]

Some "hub" federates used for implementing ADMM take in multiple inputs from different areas. The number of areas may change with the configuration, but this is fixed for a specific configuration. However, the "hub" federates need to have component_definitions.json which support any number of possible input subscriptions.

This is currently possible for "built-in" federates using a Python file, but for components only defined within a "compontn.

Requirements:

• Static file
• Dynamic number of inputs created parameterized by the wiring_diagram.json
• Checked and configurable still.