Simplify ConfigurableTask.process_results()

[baberabb]

The current process_results method has grown unwieldy and difficult to understand, with deep branching logic for different output types (for example multiple_input, 'multiple_output`) and implicit type conversions. We can simplify this by keeping the method focused on the usual case with explicit types, while more complicated scenarios can be handled by overloading the method in custom tasks.

[mfisher35]

Hi! I've refactored process_results() into smaller helper functions (e.g., _process_results_loglikelihood, etc.) to address the complexity mentioned here.

The new structure keeps the standard logic in the base class and makes it easier to override specific output types for custom tasks. I’ve also isolated mutual info handling and gold normalization into separate helpers.

Would you be open to a PR for this? Happy to polish it further if needed.