Automatic differentiation with Enzyme

[nkoukpaizan]

Issue to track progress on automatic differentiation. Includes features that were taken from #54 to limit the scope of that PR and other features as needed:

• Implement evaluateAutodiffJacobian and getAutodiffJacobian within the models. I'm open to alternative software design choices. The hope is that placing the derivative evaluation within the same compilation unit as the function will work better than trying to differentiate a code that is already compiled.
• Implement a better way to link with Enzyme. The add_custom_command approach will be hard to maintain.
• Implement a functionality test looping through different existing models to test the Jacobians.
• Implement an approach that supports sparsity detection, potentially with another tool.