Composite Model function output

[teubert]

Requirement Text
The output of composite models' function elements should be a composite model output

Background Information
Composite models combine prognostic model (i.e., subclasses of PrognosticsModel) and functions (*args) -> output in some defined way. The outputs of the composite model are currently the outputs of all of the comprised prongostics models. The output (i.e., the return) of the function members only show up in the composite model state.

We need the function return (i.e., output) to be an output of the composite model for it to work in the state estimator

Suggested Solution
Adjust the code for the composite model function output to be registered as an output instead of a state.

DoD

• Implement feature
• Add tests